Compositions of resin-linear organosiloxane block copolymers

ABSTRACT

The present disclosure provides hydrosilylation curable compositions comprising resin linear organosiloxane block copolymers comprising, among other things, from about 0.5 to about 5 mole % C 1  to C 30  hydrocarbyl group comprising at least one aliphatic unsaturated bond. Such hydrosilylation curable resin-linear organosiloxane block copolymers have significantly faster cure speed, relative to their condensation curable counterparts. A faster cure speed can be important for encapsulating electronic devices, such as light-emitting diode (LED) chip devices, particularly devices having tall structures.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national stage application filed under 35U.S.C. §371 from International Application Serial No. PCT/US2014/056350,which was filed Sep. 18, 2014, and published as WO 2015/042285 on Mar.26, 2015, and claims the benefit of U.S. Provisional Appl. Ser. No.61/879,447, filed Sep. 18, 2013, which applications and publication areincorporated by reference as if reproduced herein and made a part hereofin their entirety, and the benefit of priority of each of which isclaimed herein.

BACKGROUND

Many electronic devices use an encapsulant coating to protect electroniccomponents from environmental factors. These protective coatings must betough, durable, long lasting, easy to apply, and cure relatively quicklywithout the production of undesired byproducts. Many of the currentlyavailable coatings, however, lack toughness; are not durable; are notlong-lasting; are not easy to apply; for certain applications, do notcure quickly enough; and, in some instances, produce undesiredbyproducts upon curing. There is therefore a continuing need to identifyprotective and/or functional coatings in many areas of emergingtechnologies.

SUMMARY

Embodiment 1 relates to an organosiloxane block copolymer comprising:

-   -   40 to 90 mole percent disiloxy units of the formula [R¹        ₂SiO_(2/2)],    -   10 to 60 mole percent trisiloxy units of the formula        [R²SiO_(3/2)],    -   0.5 to 35 mole percent silanol groups [≡SiOH];        -   wherein:    -   each R¹, at each occurrence, is independently a C₁ to C₃₀        hydrocarbyl or a C₁ to C₃₀ hydrocarbyl group comprising at least        one aliphatic unsaturated bond,    -   each R², at each occurrence, is independently a C₁ to C₃₀        hydrocarbyl or a C₁ to C₃₀ hydrocarbyl group comprising at least        one aliphatic unsaturated bond;        -   wherein:    -   the disiloxy units [R¹ ₂SiO_(2/2)] are arranged in linear blocks        having an average of from 50 to 300 disiloxy units [R¹        ₂SiO_(2/2)] per linear block;    -   the trisiloxy units [R²SiO_(3/2)] are arranged in non-linear        blocks having a molecular weight of at least 500 g/mole;    -   at least 30% of the non-linear blocks are crosslinked with each        other;    -   each linear block is linked to at least one non-linear block via        —Si—O—Si— linkages;    -   the organosiloxane block copolymer has a weight average        molecular weight of at least 20,000 g/mole; and    -   the organosiloxane block copolymer comprises from about 0.5 to        about 5 mole % C₁ to C₃₀ hydrocarbyl group comprising at least        one aliphatic unsaturated bond.

Embodiment 2 relates to the organosiloxane block copolymer of Embodiment1, wherein the organosiloxane block copolymer has a weight averagemolecular weight of about 40,000 g/mole to about 250,000 g/mole.

Embodiment 3 relates to the organosiloxane block copolymer ofEmbodiments 1-2, wherein the organosiloxane block copolymer comprises 1to 35 mole percent silanol groups [≡SiOH].

Embodiment 4 relates to the organosiloxane block copolymer ofEmbodiments 1-3, wherein the organosiloxane block copolymer comprises 30to 60 mole percent trisiloxy units of the formula [R²SiO_(3/2)].

Embodiment 5 relates to a composition comprising the reaction productof:

-   -   A) a resin linear organosiloxane block copolymer comprising:    -   40 to 90 mole percent disiloxy units of the formula [R¹        ₂SiO_(2/2)],    -   10 to 60 mole percent trisiloxy units of the formula        [R²SiO_(3/2)],    -   0.5 to 35 mole percent silanol groups [≡SiOH];    -   wherein:        -   each R¹, at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation,        -   each R², at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation;    -   wherein:    -   the disiloxy units [R¹ ₂SiO_(2/2)] are arranged in linear blocks        having an average of from 50 to 300 disiloxy units [R¹        ₂SiO_(2/2)] per linear block,    -   the trisiloxy units [R²SiO_(3/2)] are arranged in non-linear        blocks having a molecular weight of at least 500 g/mole, at        least 30% of the non-linear blocks are crosslinked with each        other,    -   each linear block is linked to at least one non-linear block;        and    -   the organosiloxane block copolymer has a weight average        molecular weight of at least 20,000 g/mole; and    -   B) a compound of the formula R¹R² ₂SiX    -   wherein each R¹, at each occurrence, is independently a C₁ to        C₃₀ hydrocarbyl free of aliphatic unsaturation or a C₁ to C₃₀        hydrocarbyl group comprising at least one aliphatic unsaturated        bond,    -   each R², at each occurrence, is independently a C₁ to C₃₀        hydrocarbyl free of aliphatic unsaturation or a C₁ to C₃₀        hydrocarbyl group comprising at least one aliphatic unsaturated        bond, and    -   X is a hydrolyzable group chosen from —OR⁴, F, Cl, Br, I,        —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ is hydrogen or a C₁        to C₆ alkyl group that may be optionally substituted.

Embodiment 6 relates to the composition of Embodiment 5, wherein theresin linear organosiloxane block copolymer has a weight averagemolecular weight of about 40,000 g/mole to about 250,000 g/mole.

Embodiment 7 relates to the organosiloxane block copolymer ofEmbodiments 5-6, wherein the organosiloxane block copolymer comprises 1to 35 mole percent silanol groups [≡SiOH].

Embodiment 8 relates to the organosiloxane block copolymer ofEmbodiments 5-7, wherein the organosiloxane block copolymer comprises 30to 60 mole percent trisiloxy units of the formula [R²SiO_(3/2)].

Embodiment 9 relates to a composition comprising the reaction productof:

-   -   A) a linear organosiloxane having the formula:        R¹ _(3-p)(E)_(p)SiO(R¹ ₂SiO_(2/2))_(n)Si(E)_(p)R¹ _(3-p),        -   wherein each R¹, at each occurrence, is independently a C₁            to C₃₀ hydrocarbyl free of aliphatic unsaturation,        -   n is 50 to 300,        -   E is a hydrolyzable group chosen from OR⁴, F, Cl, Br, I,            —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ is hydrogen or a            C₁ to C₆ alkyl group, and        -   each p is, independently, 1, 2 or 3; and    -   B) an organosiloxane resin comprising unit formula:        [R¹        ₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e),        -   wherein:        -   each R¹, at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation or a C₁ to C₃₀            hydrocarbyl group comprising at least one aliphatic            unsaturated bond,        -   each R², at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation or a C₁ to C₃₀            hydrocarbyl group comprising at least one aliphatic            unsaturated bond,        -   wherein the organosiloxane resin comprises 0 to 35 mole %            silanol groups [≡SiOH], and        -   the subscripts a, b, c, d, and e represent the mole fraction            of each siloxy unit present in the organosiloxane resin and            range as follows:            -   a is about 0 to about 0.6,            -   b is about 0 to about 0.6,            -   c is about 0 to about 1,            -   d is about 0 to about 1,            -   e is about 0 to about 0.6,            -   with the provisos that b+c+d+e>0 and a+b+c+d+e≦1.

Embodiment 10 relates to a composition comprising the reaction productof:

-   -   A) a linear organosiloxane having the formula:        R¹ _(3-p)(E)_(p)SiO(R¹ ₂SiO_(2/2))_(n)Si(E)_(p)R¹ _(3-p),        -   wherein each R¹, at each occurrence, is independently a C₁            to C₃₀ hydrocarbyl free of aliphatic unsaturation,        -   n is 50 to 300,        -   E is a hydrolyzable group chosen from —OR⁴, F, Cl, Br, I,            —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ is hydrogen or a            C₁ to C₆ alkyl group, and        -   each p is, independently, 1, 2 or 3, and    -   B) an organosiloxane resin comprising unit formula:        [R¹        ₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e),        -   wherein:        -   each R¹, at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation,        -   each R², at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation,        -   wherein the organosiloxane resin comprises 0 to 35 mole %            silanol groups [≡SiOH], and        -   the subscripts a, b, c, d, and e represent the mole fraction            of each siloxy unit present in the organosiloxane resin and            range as follows:            -   a is about 0 to about 0.6,            -   b is about 0 to about 0.6,            -   c is about 0 to about 1,            -   d is about 0 to about 1,            -   e is about 0 to about 0.6,        -   with the provisos that b+c+d+e>0 and a+b+c+d+e≦1; and    -   C) a compound of the formula R¹ _(q)SiX_(4-q)        -   wherein each R¹, at each occurrence, is independently a C₁            to C₃₀ hydrocarbyl free of aliphatic unsaturation or a C₁ to            C₃₀ hydrocarbyl group comprising at least one aliphatic            unsaturated bond,        -   q is 0, 1 or 2, and,        -   each X is independently a hydrolyzable group chosen from            —OR⁴, F, Cl, Br, I, —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein            R⁴ is hydrogen or a C₁ to C₆ alkyl group that may be            optionally substituted.

Embodiment 11 relates to the composition of Embodiment 10, wherein theproduct of the contacting between A) and B) is contacted with C).

Embodiment 12 relates to the composition of Embodiments 5-11, whereinthe reaction product is contacted with a compound of the formula R⁵_(q)SiX_(4-q), wherein each R⁵ is independently a C₁ to C₈ hydrocarbylor a C₁ to C₈ halogen-substituted hydrocarbyl; and each X isindependently a hydrolyzable group chosen from —OR⁴, F, Cl, Br, I,—OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ is hydrogen or a C₁ to C₆alkyl group that may be optionally substituted.

Embodiment 13 relates to the composition of Embodiments 5-11, whereinthe reaction product is an organosiloxane block copolymer and theorganosiloxane block copolymer comprises from about 0.5 to about 5 mole% C₁ to C₃₀ hydrocarbyl group comprising at least one aliphaticunsaturated bond.

Embodiment 14 relates to the composition of Embodiment 9 or 10, whereinE is acetoxy and p is 1.

Embodiment 15 relates to the composition of Embodiments 5-14 furthercomprising a compound having unit formula:[R¹₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e)

-   -   comprising 0 to 35 mole % silanol groups [≡SiOH],    -   wherein:    -   each R¹, at each occurrence, is independently H or a C₁ to C₃₀        hydrocarbyl free of aliphatic unsaturation,    -   each R², at each occurrence, is independently H or a C₁ to C₃₀        hydrocarbyl free of aliphatic unsaturation,    -   wherein the subscripts a, b, c, d, and e represent the mole        fraction of each siloxy unit present and range as follows:        -   a is about 0 to about 0.6,        -   b is about 0 to about 0.6,        -   c is about 0 to about 1,        -   d is about 0 to about 1,        -   e is about 0 to about 0.6,    -   with the provisos that:        -   b+c+d+e>0 and a+b+c+d+e≦1, and        -   at least 1 mole % of R¹ and/or R² are H.

Embodiment 16 relates to the composition of Embodiments 5-15 furthercomprising a hydrosilylation catalyst.

Embodiment 17 relates to the composition of Embodiments 5-16, furthercomprising free resin that is not part of the block copolymer.

Embodiment 18 relates to the composition of Embodiments 5-10, whereinthe composition is curable.

Embodiment 19 relates to the curable composition of Embodiment 18,wherein the curable composition has a cure speed in Pa/min of from about1 to about 20 Pa/min at a heating rate of 5° C./min.

Embodiment 20 relates to the curable composition of Embodiment 18,wherein the curable composition is curable via at least two curingmechanisms.

Embodiment 21 relates to the curable composition of Embodiment 20,wherein said at least two curing mechanisms comprise hydrosylilationcure and condensation cure.

Embodiment 22 relates to the composition of Embodiments 5-10, whereinthe composition is solid.

Embodiment 23 relates to the composition of Embodiment 22, furthercomprising free resin that is not part of the block copolymer.

Embodiment 24 relates to the composition of Embodiment 22, wherein thesolid composition is a solid film composition.

Embodiment 25 relates to the composition of Embodiment 24, wherein thesolid film composition has an optical transmittance of at least 95% at afilm thickness of 0.5 mm or greater.

Embodiment 26 relates to the cured product of the compositions ofEmbodiments 5-10.

Embodiment 27 relates to the cured product of Embodiment 26, wherein theproduct is cured in the absence of a condensation catalyst.

Embodiment 28 relates to the cured product of Embodiment 26, wherein theproduct is cured in the presence of a phosphor or a filler.

Embodiment 29 relates to the cured product of Embodiment 26, wherein theratio of the Young's modulus of the cured product after aging for 50hours at 225° C. and the Young's modulus before aging is less than 3.

Embodiment 30 relates to the cured product of Embodiment 26, wherein thecured product generates less than 200 ppm benzene after 30 minutes at180° C.

Embodiment 31 relates to the cured product of Embodiment 26, wherein theCIE b* value after aging for 72 h at 235° C. is no more than about 6.

DESCRIPTION

The present disclosure provides a process for preparing certain “resinlinear” organosiloxane block copolymers, as well as curable and solidcompositions comprising “resin linear” organosiloxane block copolymers.The “resin-linear” organosiloxane block copolymers contain a certain,relatively low amount (in mole %) of unsaturated groups so that they canbe cured at least via hydrosilylation, though “dual cure” mechanisms arealso contemplated. In embodiments encompassing resin linearorganosiloxane block copolymers having dual cure mechanisms,hydrosilylation can be one cure mechanism. But, in addition to having acertain amount (in mole %) of unsaturated groups, the resin linearorganosiloxane block copolymers can also comprise other reactivefunctionality (e.g., silanol, epoxide groups, cyanate ester groups,azide alkyne groups and the like) that can provide at least a secondcure mechanism, including a condensation cure mechanism, Diels-Aldercure, azide-alkyne cycloaddition cure, radical cure, UV or radicalacrylate cure, UV epoxy cure, Michael addition, and all reactions thatare classified as “click chemistry.”

It has been surprisingly and unexpectedly found that hydrosilylationcurable resin-linear organosiloxane block copolymers with relatively lowamounts of unsaturated groups have significantly faster cure speed,relative to their condensation curable counterparts. The faster curespeed has been instrumental for encapsulating and curing electronicdevices, such as light-emitting diodes (LED), with high throughput,thereby lowering the total cost of the process and assisting in generaladoption of solid state lighting. LED chip devices also typicallycontain tall structures like the chip and diode, which are particularlychallenging to encapsulate, for example, by lamination processes. Atunable fast cure speed system can offer the level of control needed tobe successful in these situations. In addition to having a fast curespeed, the hydrosilylation curable organosiloxane block copolymersexhibit, among other things, low tack and high shelf stability resultingfrom a relatively high resin glass transition temperature (T_(g)). Otherbenefits associated with the “resin linear” organosiloxane blockcopolymers, as well as curable and solid compositions comprising “resinlinear” organosiloxane block copolymers, described herein include, butare not limited to, good dissipative or stress relaxation behavior,which assists in stress dissipation in LED devices; the ability toaccommodate phosphor particles without detrimental impact on cure speed.

Organosiloxane Block Copolymers

In some embodiments, the “resin linear” organosiloxane block copolymersare organosiloxane block copolymers comprising:

-   -   40 to 90 mole percent disiloxy units of the formula [R¹        ₂SiO_(2/2)],    -   10 to 60 mole percent trisiloxy units of the formula        [R²SiO_(3/2)],    -   0.5 to 35 mole percent silanol groups [≡SiOH];    -   wherein:        -   each R¹, at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl or a C₁ to C₃₀ hydrocarbyl group comprising at            least one aliphatic unsaturated bond,        -   each R², at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl or a C₁ to C₃₀ hydrocarbyl group comprising at            least one aliphatic unsaturated bond;    -   wherein:    -   the disiloxy units [R¹ ₂SiO_(2/2)] (D) are arranged in linear        blocks having an average of from 10 to 400 disiloxy units [R¹        ₂SiO_(2/2)] per linear block;    -   the trisiloxy units [R²SiO_(3/2)] (T) are arranged in non-linear        blocks having a molecular weight of at least 500 g/mole;    -   at least 30% of the non-linear blocks are crosslinked with each        other;    -   each linear block is linked to at least one non-linear block via        —Si—O—Si— linkages;    -   the organosiloxane block copolymer has a weight average        molecular weight of at least 20,000 g/mole; and    -   the organosiloxane block copolymer comprises from about 0.5 to        about 5 mole % C₁ to C₃₀ hydrocarbyl group comprising at least        one aliphatic unsaturated bond.

As used herein “organosiloxane block copolymers” or “resin-linearorganosiloxane block copolymers” refer to organopolysiloxanes containing“linear” D siloxy units in combination with “resin” T siloxy units. Insome embodiments, the organosiloxane copolymers are “block” copolymers,as opposed to “random” copolymers. As such, the “resin-linearorganosiloxane block copolymers” of the disclosed embodiments refer toorganopolysiloxanes containing D and T siloxy units, where the D units(i.e., [R¹ ₂SiO_(2/2)] units) are primarily bonded together to formpolymeric chains having, in some embodiments, an average of from 10 to400 D units (e.g., an average of from about 10 to about 350 D units;about 10 to about 300 D units; about 10 to about 200 D units; about 10to about 100 D units; about 50 to about 400 D units; about 100 to about400 D units; about 150 to about 400 D units; about 200 to about 400 Dunits; about 300 to about 400 D units; about 50 to about 300 D units;about 100 to about 300 D units; about 150 to about 300 D units; about200 to about 300 D units; about 100 to about 150 D units, about 115 toabout 125 D units, about 90 to about 170 D units or about 110 to about140 D units), which are referred herein as “linear blocks.”

The T units (i.e., [R²SiO_(3/2)]) are, in some embodiments, primarilybonded to each other to form branched polymeric chains, which arereferred to as “non-linear blocks.” In some embodiments, a significantnumber of these non-linear blocks may further aggregate to form“nano-domains” when solid forms of the block copolymer are provided. Insome embodiments, these nano-domains form a phase separate from a phaseformed from linear blocks having D units, such that a resin-rich phaseforms. In some embodiments, the disiloxy units [R¹ ₂SiO_(2/2)] arearranged in linear blocks having an average of from 10 to 400 disiloxyunits [R¹ ₂SiO_(2/2)] per linear block (e.g., an average of from about10 to about 350 D units; about 10 to about 300 D units; about 10 toabout 200 D units; about 10 to about 100 D units; about 50 to about 400D units; about 100 to about 400 D units; about 150 to about 400 D units;about 200 to about 400 D units; about 300 to about 400 D units; about 50to about 300 D units; about 100 to about 300 D units; about 150 to about300 D units; about 200 to about 300 D units; about 100 to about 150 Dunits, about 115 to about 125 D units, about 90 to about 170 D units orabout 110 to about 140 D units), and the trisiloxy units [R²SiO_(3/2)]are arranged in non-linear blocks having a molecular weight of at least500 g/mole and at least 30% of the non-linear blocks are crosslinkedwith each other.

In some embodiments, the non-linear blocks have a number averagemolecular weight of at least 500 g/mole, e.g., at least 1000 g/mole, atleast 2000 g/mole, at least 3000 g/mole, at least 4000 g/mole, at least5000 g/mole, at least 6000 g/mole, at least 7000 g/mole or at least 8000g/mole; or have a molecular weight of from about 500 g/mole to 8000g/mole, from about 500 g/mole to 7000 g/mole, from about 500 g/mole to6000 g/mole, from about 500 g/mole to 5000 g/mole, from about 500 g/moleto about 4000 g/mole, from about 500 g/mole to about 3000 g/mole, fromabout 500 g/mole to about 2000 g/mole, from about 500 g/mole to about1000 g/mole, from about 1000 g/mole to 2000 g/mole, from about 1000g/mole to about 1500 g/mole, from about 1000 g/mole to about 1200g/mole, from about 1000 g/mole to 3000 g/mole, from about 1000 g/mole toabout 2500 g/mole, from about 1000 g/mole to about 4000 g/mole, fromabout 1000 g/mole to 5000 g/mole, from about 1000 g/mole to 6000 g/mole,from about 1000 g/mole to 7000 g/mole, from about 1000 g/mole to 8000g/mole, from about 2000 g/mole to about 3000 g/mole, from about 2000g/mole to about 4000 g/mole, from about 2000 g/mole to 5000 g/mole, fromabout 2000 g/mole to 6000 g/mole, from about 2000 g/mole to 7000 g/moleor from about 2000 g/mole to 8000 g/mole.

In some embodiments, at least 30% of the non-linear blocks arecrosslinked with each other, e.g., at least 40% of the non-linear blocksare crosslinked with each other; at least 50% of the non-linear blocksare crosslinked with each other; at least 60% of the non-linear blocksare crosslinked with each other; at least 70% of the non-linear blocksare crosslinked with each other; or at least 80% of the non-linearblocks are crosslinked with each other, wherein all of the percentagesgiven herein to indicate percent non-linear blocks that are crosslinkedare in weight percent. In other embodiments, from about 30% to about 80%of the non-linear blocks are crosslinked with each other; from about 30%to about 70% of the non-linear blocks are crosslinked with each other;from about 30% to about 60% of the non-linear blocks are crosslinkedwith each other; from about 30% to about 50% of the non-linear blocksare crosslinked with each other; from about 30% to about 40% of thenon-linear blocks are crosslinked with each other; from about 40% toabout 80% of the non-linear blocks are crosslinked with each other; fromabout 40% to about 70% of the non-linear blocks are crosslinked witheach other; from about 40% to about 60% of the non-linear blocks arecrosslinked with each other; from about 40% to about 50% of thenon-linear blocks are crosslinked with each other; from about 50% toabout 80% of the non-linear blocks are crosslinked with each other; fromabout 50% to about 70% of the non-linear blocks are crosslinked witheach other; from about 55% to about 70% of the non-linear blocks arecrosslinked with each other, from about 50% to about 60% of thenon-linear blocks are crosslinked with each other; from about 60% toabout 80% of the non-linear blocks are crosslinked with each other; orfrom about 60% to about 70% of the non-linear blocks are crosslinkedwith each other.

The crosslinking of the non-linear blocks may be accomplished via avariety of chemical mechanisms and/or moieties. For example,crosslinking of non-linear blocks within the block copolymer may resultfrom the condensation of residual silanol groups present in thenon-linear blocks of the copolymer.

In some embodiments, the organosiloxane block copolymers of theembodiments described herein comprise 40 to 90 mole percent disiloxyunits of the formula [R¹ ₂SiO_(2/2)], e.g., 50 to 90 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 60 to 90 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 65 to 90 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 70 to 90 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; or 80 to 90 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 40 to 80 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 40 to 70 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 40 to 60 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 40 to 50 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 50 to 80 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 50 to 70 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 50 to 60 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 60 to 80 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; 60 to 70 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)]; or 70 to 80 mole percentdisiloxy units of the formula [R¹ ₂SiO_(2/2)].

In some embodiments, the organosiloxane block copolymers of theembodiments described herein comprise 10 to 60 mole percent trisiloxyunits of the formula [R²SiO_(3/2)], e.g., 10 to 20 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 10 to 30 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 10 to 35 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 10 to 40 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 10 to 50 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 20 to 30 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 20 to 35 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 20 to 40 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 20 to 50 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 20 to 60 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 30 to 40 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 30 to 50 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 30 to 60 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; 40 to 50 mole percenttrisiloxy units of the formula [R²SiO_(3/2)]; or 40 to 60 mole percenttrisiloxy units of the formula [R²SiO_(3/2)].

It should be understood that the organosiloxane block copolymers of theembodiments described herein may contain additional siloxy units, suchas M siloxy units, Q siloxy units, other unique D or T siloxy units (forexample, having organic groups other than R¹ or R²), provided that theorganosiloxane block copolymer contains the mole fractions of thedisiloxy and trisiloxy units as described herein and comprises fromabout 0.5 to about 5 mole % (e.g., about 0.5 to about 1 mole %, about0.5 to about 4.5 mole %, about 1 to about 4 mole %, about 2 to about 3mole %, about 2 to about 4 mole %, about 1 to about 5 mole % or about 2to about 5 mole %) C₁ to C₃₀ hydrocarbyl group comprising at least onealiphatic unsaturated bond.

In some embodiments, the resin-linear organosiloxane block copolymersalso contain silanol groups (≡SiOH). The amount of silanol groupspresent on the organosiloxane block copolymer may vary from 0.5 to 35mole percent silanol groups [≡SiOH], alternatively from 2 to 32 molepercent silanol groups [≡SiOH], alternatively from 8 to 22 mole percentsilanol groups [≡SiOH], alternatively from 10 to 20 mole percent silanolgroups [≡SiOH], alternatively from 15 to 20 mole percent silanol groups[≡SiOH], alternatively from 12 to 22 mole percent silanol groups[≡SiOH], alternatively from 15 to 25 mole percent silanol groups[≡SiOH], alternatively from 15 to 35 mole percent silanol groups [≡SiOH]or alternatively 1 to 35 mole percent silanol groups. The silanol groupsmay be present on any siloxy units within the organosiloxane blockcopolymer. The amount described herein represents the total amount ofsilanol groups found in the organosiloxane block copolymer. In someembodiments, the majority (e.g., greater than 75%, greater than 80%,greater than 90%; from about 75% to about 90%, from about 80% to about90%, or from about 75% to about 85%) of the silanol groups will resideon the trisiloxy units, i.e., the resin component of the blockcopolymer. Although not wishing to be bound by any theory, the silanolgroups present on the resin component of the organosiloxane blockcopolymer allows for the block copolymer to further react or cure atelevated temperatures.

At each occurrence, each R¹, when mentioned herein, may independently bea C₁ to C₃₀ hydrocarbyl (e.g., a C₁ to C₂₀ hydrocarbyl, a C₁ to C₁₀hydrocarbyl or a C₁ to C₆ hydrocarbyl), where the hydrocarbyl group isfree of aliphatic unsaturation and may independently be an alkyl, aryl,or alkylaryl group. Each R¹, at each occurrence, may independently be aC₁ to C₃₀ alkyl group, alternatively, at each occurrence, each R¹ may bea C₁ to C₁₈ alkyl group. Alternatively each R¹, at each occurrence, maybe a C₁ to C₆ alkyl group such as methyl, ethyl, propyl, butyl, pentyl,or hexyl. Alternatively each R¹, at each occurrence, may be methyl. EachR¹, at each occurrence, may be an aryl group, such as phenyl, naphthyl,or an anthryl group. Alternatively, each R¹, at each occurrence, may beany combination of the aforementioned alkyl or aryl groups such that, insome embodiments, each disiloxy unit may have two alkyl groups (e.g.,two methyl groups); two aryl groups (e.g., two phenyl groups); or analkyl (e.g., methyl) and an aryl group (e.g., phenyl). Alternatively,each R¹, at each occurrence, may be phenyl or methyl, so long as theorganosiloxane block copolymer comprises from about 0.5 to about 5 mole% (e.g., about 0.5 to about 1 mole %, about 0.5 to about 4.5 mole %,about 1 to about 4 mole %, about 2 to about 3 mole %, about 2 to about 4mole %, about 1 to about 5 mole % or about 2 to about 5 mole %) C₁ toC₃₀ hydrocarbyl group comprising at least one aliphatic unsaturatedbond.

In some embodiments, at each occurrence, each R¹, when mentioned herein,is independently a C₁ to C₃₀ hydrocarbyl, where the hydrocarbyl groupcomprises at least one aliphatic unsaturated bond. Examples of aliphaticunsaturated bonds include, but are not limited to, alkenyl or alkynylbonds. In some embodiments, the aliphatic unsaturated bond is a terminaldouble bond. Examples of C₂ to C₃₀ (e.g., C₂ to C₂₀; C₂ to C₁₂; C₂ toC₈; or C₂ to C₄) hydrocarbyl groups include, but are not limited to,H₂C═CH—, H₂C═CHCH₂—, H₂C═C(CH₃)CH₂—, H₂C═CHC(CH₃)₂—, H₂C═CHCH₂CH₂—,H₂C═CHCH₂CH₂CH₂—, H₂C═CHCH₂CH₂CH₂CH₂—, and the like. Other examples ofC₂ to C₃₀ hydrocarbyl groups include, but are not limited to HC≡C—,HC≡CCH₂—, HC≡CCH(CH₃)—, HC≡CC(CH₃)₂—, and HC≡CC(CH₃)₂CH₂—. AlternativelyR¹ is a vinyl group, H₂C═CH—.

At each occurrence, each R², when mentioned herein, may independently bea C₁ to C₃₀ hydrocarbyl (e.g., a C₁ to C₂₀ hydrocarbyl, a C₁ to C₁₀hydrocarbyl or a C₁ to C₆ hydrocarbyl), where the hydrocarbyl group isfree of aliphatic unsaturation and may independently be an alkyl, aryl,or alkylaryl group. Each R², at each occurrence, may independently be aC₁ to C₃₀ alkyl group, alternatively, at each occurrence, each R² may bea C₁ to C₁₈ alkyl group. Alternatively each R², at each occurrence, maybe a C₁ to C₆ alkyl group such as methyl, ethyl, propyl, butyl, pentyl,or hexyl. Alternatively each R², at each occurrence, may be methyl. EachR², at each occurrence, may be an aryl group, such as phenyl, naphthyl,or an anthryl group. Alternatively, each R², at each occurrence, may beany combination of the aforementioned alkyl or aryl groups such that, insome embodiments, each disiloxy unit may have two alkyl groups (e.g.,two methyl groups); two aryl groups (e.g., two phenyl groups); or analkyl (e.g., methyl) and an aryl group (e.g., phenyl). Alternatively,each R², at each occurrence, may be phenyl or methyl, so long as theorganosiloxane block copolymer comprises from about 0.5 to about 5 mole% (e.g., about 0.5 to about 1 mole %, about 0.5 to about 4.5 mole %,about 1 to about 4 mole %, about 2 to about 3 mole %, about 2 to about 4mole %, about 1 to about 5 mole % or about 2 to about 5 mole %) C₁ toC₃₀ hydrocarbyl group comprising at least one aliphatic unsaturatedbond.

In some embodiments, at each occurrence, each R², when mentioned herein,is independently a C₁ to C₃₀ hydrocarbyl, where the hydrocarbyl groupcomprises at least one aliphatic unsaturated bond, as the term isdefined herein.

As used throughout the specification, “hydrocarbyl” also includessubstituted hydrocarbyl groups. “Substituted” as used throughout thespecification refers broadly to replacement of one or more of thehydrogen atoms of the group with substituents known to those skilled inthe art and resulting in a stable compound as described herein. Examplesof suitable substituents include, but are not limited to, alkyl,alkenyl, alkynyl, cycloalkyl, aryl, alkaryl, hydroxy, alkoxy, aryloxy,carboxy (i.e., CO₂H), carboxyalkyl, carboxyaryl, cyano, cyanate ester(i.e., an —OCN group), silyl, siloxyl, phosphine, halogen, sulfurcontaining group, nitro, epoxy (where two adjacent carbon atoms, alongwith an oxygen atom to which they are attached, form an epoxide group)and the like. Substituted hydrocabyl also includes halogen substitutedhydrocarbyls, where the halogen may be fluorine, chlorine, bromine orcombinations thereof.

The organosiloxane block copolymers of the embodiments described hereinhave a weight average molecular weight (M_(w)) of at least 20,000g/mole, alternatively a weight average molecular weight of at least40,000 g/mole, alternatively a weight average molecular weight of atleast 50,000 g/mole, alternatively a weight average molecular weight ofat least 60,000 g/mole, alternatively a weight average molecular weightof at least 80,000 g/mole, or alternatively a weight average molecularweight of at least 100,000 g/mole. In some embodiments, theorganosiloxane block copolymers of the embodiments described herein havea weight average molecular weight (M_(w)) of from about 20,000 g/mole toabout 250,000 g/mole, from about 40,000 g/mole to about 250,000 g/mole,from about 50,000 g/mole to about 250,000 g/mole or from about 100,000g/mole to about 250,000 g/mole, alternatively a weight average molecularweight of from about 45,000 g/mole to about 100,000 g/mole,alternatively a weight average molecular weight of from about 50,000g/mole to about 100,000 g/mole, alternatively a weight average molecularweight of from about 50,000 g/mole to about 80,000 g/mole, alternativelya weight average molecular weight of from about 50,000 g/mole to about70,000 g/mole, alternatively a weight average molecular weight of fromabout 50,000 g/mole to about 60,000 g/mole. In some embodiments, theorganosiloxane block copolymers of the embodiments described herein havea number average molecular weight (M_(n)) of from about 15,000 to about50,000 g/mole; from about 15,000 to about 30,000 g/mole; from about20,000 to about 30,000 g/mole; or from about 20,000 to about 25,000g/mole. The average molecular weight may be readily determined using GelPermeation Chromatography (GPC) techniques, such as those described inthe Examples.

Methods of Making Organosiloxane Block Copolymers

In some embodiments, the resin-linear organosiloxane block copolymers ofthe embodiments of the present invention may be prepared by a methodcomprising contacting (e.g., reacting):

-   -   A) a resin linear organosiloxane block copolymer comprising:    -   40 to 90 mole percent disiloxy units of the formula [R¹        ₂SiO_(2/2)],    -   10 to 60 mole percent trisiloxy units of the formula        [R²SiO_(3/2)],    -   0.5 to 35 mole percent silanol groups [≡SiOH];    -   wherein:        -   each R¹, at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation,        -   each R², at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation;    -   wherein:    -   the disiloxy units [R¹ ₂SiO_(2/2)] are arranged in linear blocks        having an average of from 10 to 400 disiloxy units [R¹        ₂SiO_(2/2)] per linear block,    -   the trisiloxy units [R²SiO_(3/2)] are arranged in non-linear        blocks having a molecular weight of at least 500 g/mole, at        least 30% of the non-linear blocks are crosslinked with each        other,    -   each linear block is linked to at least one non-linear block via        —Si—O—Si— linkages; and    -   the organosiloxane block copolymer has a weight average        molecular weight of at least 20,000 g/mole; with    -   B) a compound of the formula R¹R² ₂SiX    -   wherein each R¹, at each occurrence, is independently a C₁ to        C₃₀ hydrocarbyl free of aliphatic unsaturation or a C₁ to C₃₀        hydrocarbyl group comprising at least one aliphatic unsaturated        bond,    -   each R², at each occurrence, is independently a C₁ to C₃₀        hydrocarbyl free of aliphatic unsaturation or a C₁ to C₃₀        hydrocarbyl group comprising at least one aliphatic unsaturated        bond, and    -   X is a hydrolyzable group chosen from —OR⁴, F, Cl, Br, I,        —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ is hydrogen or a C₁        to C₆ alkyl group that may be optionally substituted.

In other embodiments, the resin-linear organosiloxane block copolymersof the embodiments of the present invention may be prepared by a methodcomprising contacting:

-   -   A) a linear organosiloxane having the formula:        R¹ _(3-p)(E)_(p)SiO(R¹ ₂SiO_(2/2))_(n)Si(E)_(p)R¹ _(3-p),        -   wherein each R¹, at each occurrence, is independently a C₁            to C₃₀ hydrocarbyl free of aliphatic unsaturation,        -   n is 10 to 400,        -   E is a hydrolyzable group chosen from —OR⁴, F, Cl, Br, I,            —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ is hydrogen or a            C₁ to C₆ alkyl group, and        -   each p is, independently, 1, 2 or 3; and    -   B) an organosiloxane resin comprising unit formula:        [R¹        ₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e),        -   wherein each R¹, at each occurrence, is independently a C₁            to C₃₀ hydrocarbyl free of aliphatic unsaturation or a C₁ to            C₃₀ hydrocarbyl group comprising at least one aliphatic            unsaturated bond,        -   each R², at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation or a C₁ to C₃₀            hydrocarbyl group comprising at least one aliphatic            unsaturated bond,        -   wherein the organosiloxane resin comprises 0 to 35 mole %            silanol groups [≡SiOH], and        -   the subscripts a, b, c, d, and e represent the mole fraction            of each siloxy unit present in the organosiloxane resin and            range as follows:            -   a is about 0 to about 0.6,            -   b is about 0 to about 1,            -   c is about 0 to about 1,            -   d is about 0 to about 1,            -   e is about 0 to about 0.6,            -   with the provisos that b+c+d+e>0 and a+b+c+d+e≦1.

In still other embodiments, the resin-linear organosiloxane blockcopolymers of the embodiments of the present invention may be preparedby a method comprising contacting:

-   -   A) a linear organosiloxane having the formula:        R¹ _(3-p)(E)_(p)SiO(R¹ ₂SiO_(2/2))_(n)Si(E)_(p)R¹ _(3-p),        -   wherein each R¹, at each occurrence, is independently a C₁            to C₃₀ hydrocarbyl free of aliphatic unsaturation,        -   n is 10 to 400,        -   E is a hydrolyzable group chosen from —OR⁴, F, Cl, Br, I,            —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ is hydrogen or a            C₁ to C₆ alkyl group, and        -   each p is, independently, 1, 2 or 3, and    -   B) an organosiloxane resin comprising unit formula:        [R¹        ₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e),        -   wherein each R¹, at each occurrence, is independently a C₁            to C₃₀ hydrocarbyl free of aliphatic unsaturation,        -   each R², at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation,        -   wherein the organosiloxane resin comprises 0 to 35 mole %            silanol groups [≡SiOH], and        -   the subscripts a, b, c, d, and e represent the mole fraction            of each siloxy unit present in the organosiloxane resin and            range as follows:            -   a is about 0 to about 0.6,            -   b is about 0 to about 0.6,            -   c is about 0 to about 1,            -   d is about 0 to about 1,            -   e is about 0 to about 0.6,        -   with the provisos that b+c+d+e>0 and a+b+c+d+e≦1; and    -   C) a compound of the formula R¹ _(q)SiX_(4-q)        -   wherein each R¹, at each occurrence, is independently a C₁            to C₃₀ hydrocarbyl free of aliphatic unsaturation or a C₁ to            C₃₀ hydrocarbyl group comprising at least one aliphatic            unsaturated bond,        -   q is 0, 1 or 2, and,        -   each X is independently a hydrolyzable group chosen from            —OR⁴, F, Cl, Br, I, —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein            R⁴ is hydrogen or a C₁ to C₆ alkyl group that may be            optionally substituted;            wherein the “contacting may be performed in any suitable            order. For example, A) and B) may be contacted first,            followed by contacting with C). Alternatively, A) and C) may            be contacted first, followed by contacting with B); B)            and C) may be contacted first, followed by contacting with            A); or A), B), and C) may be contacted with each other            substantially at the same time. In some embodiments, the            product of contacting A) and B) is contacted with C).

The methods of making the organosiloxane block copolymers describedherein, in some embodiments, yield a reaction product that is anorganosiloxane block copolymers comprising:

-   -   40 to 90 mole percent disiloxy units of the formula [R¹        ₂SiO_(2/2)],    -   10 to 60 mole percent trisiloxy units of the formula        [R²SiO_(3/2)],    -   0.5 to 35 mole percent silanol groups [≡SiOH];    -   wherein:        -   each R¹, at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl or a C₁ to C₃₀ hydrocarbyl group comprising at            least one aliphatic unsaturated bond,        -   each R², at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl or a C₁ to C₃₀ hydrocarbyl group comprising at            least one aliphatic unsaturated bond;    -   wherein:    -   the disiloxy units [R¹ ₂SiO_(2/2)] are arranged in linear blocks        having an average of from 10 to 400 disiloxy units [R¹        ₂SiO_(2/2)] per linear block;    -   the trisiloxy units [R²SiO_(3/2)] are arranged in non-linear        blocks having a molecular weight of at least 500 g/mole;    -   at least 30% of the non-linear blocks are crosslinked with each        other;    -   each linear block is linked to at least one non-linear block via        —Si—O—Si— linkages;    -   the organosiloxane block copolymer has a weight average        molecular weight of at least 20,000 g/mole; and    -   the organosiloxane block copolymer comprises from about 0.5 to        about 5 mole % C₁ to C₃₀ hydrocarbyl group comprising at least        one aliphatic unsaturated bond.

In some embodiments, such organosiloxane block copolymer reactionproducts may be contacted with a compound of the formula R⁵_(q)SiX_(4-q), wherein each R⁵ is independently a C₁ to C₈ hydrocarbyl(e.g., C₁ to C₈ alkyl group, or alternatively a phenyl group, oralternatively R⁵ is methyl, ethyl, or a combination of methyl and ethyl)or a C₁ to C₈ halogen-substituted hydrocarbyl; and each X isindependently a hydrolyzable group chosen from —OR⁴, F, Cl, Br, I,—OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ is hydrogen or a C₁ to C₆alkyl group that may be optionally substituted.

In one embodiment, the compound of the formula R⁵ _(q)SiX_(4-q) is analkyltriacetoxysilane, such as methyltriacetoxysilane,ethyltriacetoxysilane, or a combination of both. Commercially availablerepresentative alkyltriacetoxysilanes include ETS-900 (Dow CorningCorp., Midland, Mich.), methyl tris(methylethylketoxime)silane (MTO),methyl triacetoxysilane, ethyl triacetoxysilane, tetraacetoxysilane,tetraoximesilane, dimethyl diacetoxysilane, dimethyl dioximesilane, andmethyl tris(methylmethylketoxime)silane. In some embodiments, anorganosiloxane block copolymer reaction product may be contacted with acompound of the formula R⁵ _(q)SiX_(4-q) so as to introduce groups intothe organosiloxane block copolymer that cure by a moisture curemechanism following, e.g., a hydrosilylation cure.

The Linear Organosiloxane

The linear organosiloxane having the formula R¹ _(3-p)(E)_(p)SiO(R¹₂SiO_(2/2))_(n)Si(E)_(p)R¹ _(3-p), wherein each R¹, at each occurrence,is independently a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation;n is 10 to 400; E is a hydrolyzable group chosen from —OR⁴, F, Cl, Br,I, —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ is hydrogen or a C₁ to C₆alkyl group.

The subscript “n” may be considered as the degree of polymerization (dp)of the linear organosiloxane and may vary from 10 to 400 (e.g., anaverage of from about 10 to about 350 D units; about 10 to about 300 Dunits; about 10 to about 200 D units; about 10 to about 100 D units;about 50 to about 400 D units; about 100 to about 400 D units; about 150to about 400 D units; about 200 to about 400 D units; about 300 to about400 D units; about 50 to about 300 D units; about 100 to about 300 Dunits; about 150 to about 300 D units; about 200 to about 300 D units;about 100 to about 150 D units, about 115 to about 125 D units, about 90to about 170 D units or about 110 to about 140 D units).

While the organosiloxane having the formula R¹ _(3-p) (E)_(p)SiO(R¹₂SiO_(2/2))_(n)Si(E)_(p)R¹ _(3-p) is described as a linear, one skilledin the art recognizes that the linear organosiloxane may comprise asmall amount of alternative siloxy units, such a T (R¹SiO_(3/2)) siloxyunits. As such, the organosiloxane may be considered as being“predominately” linear by having a majority of D (R¹ ₂SiO_(2/2)) siloxyunits. Furthermore, the linear organosiloxane may be a combination ofseveral linear organosiloxanes. Still further, the linear organosiloxanemay comprise silanol groups. In some embodiments, the linearorganosiloxane comprises from about 0.5 to about 5 mole % silanolgroups, e.g., from about 1 mole % to about 3 mole %; from about 1 mole %to about 2 mole % or from about 1 mole % to about 1.5 mole % silanolgroups.

The Organosiloxane Resin

Organosiloxane resins comprising unit formula [R¹₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e),and methods for preparing them, wherein each R¹, at each occurrence, isindependently a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation andeach R², at each occurrence, is independently a C₁ to C₃₀ hydrocarbylfree of aliphatic unsaturation, are known in the art. See, e.g.,Published PCT Application Nos. WO2012/040302 and WO2012/040305, whichare incorporated herein by reference in their entirety. In someembodiments, they are prepared by hydrolyzing an organosilane havingthree hydrolyzable groups on the silicon atom, such as a halogen or analkoxy group in an organic solvent. A representative example for thepreparation of a silsesquioxane resin may be found in U.S. Pat. No.5,075,103. Furthermore, many organosiloxane resins are availablecommercially and sold either as a solid (flake or powder), or dissolvedin an organic solvent. Suitable, non-limiting, commercially availableorganosiloxane resins include; Dow Corning® 217 Flake Resin, 233 Flake,220 Flake, 249 Flake, 255 Flake, Z-6018 Flake (Dow Corning Corporation,Midland Mich.).

Organosiloxane resins comprising unit formula [R¹₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e),and methods for preparing them, wherein each R¹, at each occurrence, isindependently a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation ora C₁ to C₃₀ hydrocarbyl group comprising at least one aliphaticunsaturated bond and each R², at each occurrence, is independently a C₁to C₃₀ hydrocarbyl free of aliphatic unsaturation or a C₁ to C₃₀hydrocarbyl group comprising at least one aliphatic unsaturated bond,may be made in a similar fashion.

The Compound of the Formula R¹R² ₂SiX

In some embodiments, a C₁ to C₃₀ hydrocarbyl group comprising at leastone aliphatic unsaturated bond is introduced into the organosiloxaneblock copolymers of the embodiments of the present invention bycontacting (e.g., reacting) a resin linear organosiloxane blockcopolymer comprising:

-   -   40 to 90 mole percent disiloxy units of the formula [R¹        ₂SiO_(2/2)],    -   10 to 60 mole percent trisiloxy units of the formula        [R²SiO_(3/2)],    -   0.5 to 35 mole percent silanol groups [≡SiOH];    -   wherein:        -   each R¹, at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation,        -   each R², at each occurrence, is independently a C₁ to C₃₀            hydrocarbyl free of aliphatic unsaturation;    -   wherein:    -   the disiloxy units [R¹ ₂SiO_(2/2)] are arranged in linear blocks        having an average of from 10 to 400 disiloxy units [R¹        ₂SiO_(2/2)] per linear block,    -   the trisiloxy units [R²SiO_(3/2)] are arranged in non-linear        blocks having a molecular weight of at least 500 g/mole, at        least 30% of the non-linear blocks are crosslinked with each        other,    -   each linear block is linked to at least one non-linear block via        —Si—O—Si— linkages; and    -   the organosiloxane block copolymer has a weight average        molecular weight of at least 20,000 g/mole; or        organosiloxane resins comprising unit formula [R¹        ₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e);        with a compound of the formula R¹R² ₂SiX, wherein each R¹, at        each occurrence, is independently a C₁ to C₃₀ hydrocarbyl or a        C₁ to C₃₀ hydrocarbyl group comprising at least one aliphatic        unsaturated bond, each R², at each occurrence, is independently        a C₁ to C₃₀ hydrocarbyl or a C₁ to C₃₀ hydrocarbyl group        comprising at least one aliphatic unsaturated bond, and X is a        hydrolyzable group chosen from —OR⁴, F, Cl, Br, I, —OC(O)R⁴,        —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ is hydrogen or a C₁ to C₆        alkyl group that may be optionally substituted.

In one embodiment, the compound of the formula R¹R² ₂SiX may be acompound of the formula (vinyl)R² ₂SiX, (vinyl)R² ₂SiCl,(vinyl)(CH₃)₂SiX, (vinyl)(CH₃)₂SiCl, (vinyl)(phenyl)₂SiX,(vinyl)(phenyl)₂SiCl, (vinyl-phenyl)R² ₂SiX or (vinyl-phenyl)R² ₂SiCl

The amount of organosilane having the formula R¹R² ₂SiX, when used, mayvary, but, in some embodiments, is an amount sufficient to ultimatelyprovide an organosiloxane block copolymer comprising from about 0.5 toabout 20 mole % (e.g., about 0.5 to about 1 mole %, about 0.5 to about4.5 mole %, about 1 to about 4 mole %, about 2 to about 3 mole %, about2 to about 4 mole %, about 1 to about 5 mole %, about 2 to about 5 mole%, about 2 to about 10 mole %, about 5 to about 10 mole %, about 5 toabout 15 mole % about 10 to about 20 mole % or about 5 to about 20 mole%) C₁ to C₃₀ hydrocarbyl group comprising at least one aliphaticunsaturated bond.

Curable Resin-Linear Organosiloxane Block Copolymer Compositions

The present disclosure also provides curable compositions comprisingresin linear organosiloxane block copolymers comprising, among otherthings, from about 0.5 to about 5 mole % C₁ to C₃₀ hydrocarbyl groupcomprising at least one aliphatic unsaturated bond and a suitablesolvent (e.g., an aromatic solvent, such as benzene, toluene, xylene, orcombinations thereof). The curable compositions may be cured via ahydrosilylation reaction in the presence of a compound having unitformula:[R¹₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e)

-   -   comprising 0 to 35 mole % silanol groups [≡SiOH],    -   wherein:    -   each R¹, at each occurrence, is independently H or a C₁ to C₃₀        hydrocarbyl free of aliphatic unsaturation,    -   each R², at each occurrence, is independently H or a C₁ to C₃₀        hydrocarbyl free of aliphatic unsaturation,    -   wherein the subscripts a, b, c, d, and e represent the mole        fraction of each siloxy unit present and range as follows:        -   a is about 0 to about 0.6,        -   b is about 0 to about 0.6,        -   c is about 0 to about 1,        -   d is about 0 to about 1,        -   e is about 0 to about 0.6,    -   with the provisos that:        -   b+c+d+e>0 and a+b+c+d+e≦1, and        -   at least about 1 mole % (e.g., at least about 5 mole %, at            least about 10 mole %, at least about 15 mole % or at least            about 20 mole %; or from about 1 to about 20 mole %, about 1            to about 10 mole % or about 1 to about 5 mole %) of R¹            and/or R² are H.

The present disclosure also provides curable compositions comprisingresin linear organosiloxane block copolymers comprising, among otherthings, from about 0.5 to about 5 mole % C₁ to C₃₀ hydrocarbyl groupcomprising at least one aliphatic unsaturated bond and a suitablesolvent (e.g., an aromatic solvent, such as benzene, toluene, xylene, orcombinations thereof). The curable compositions may be cured via ahydrosilylation reaction in the presence of a compound having unitformula:[R¹₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e)

-   -   comprising 0 to 35 mole % silanol groups [≡SiOH],    -   wherein:    -   each R¹, at each occurrence, is independently H, a silane        radical of the formula —[R⁶R⁷Si]_(k)[R⁶R⁷SiH] (wherein R⁶, R⁷        are independently a H or a C₁ to C₃₀ hydrocarbyl free of        aliphatic unsaturation, k is an integer from 0 to 10) or a C₁ to        C₃₀ hydrocarbyl free of aliphatic unsaturation,    -   each R², at each occurrence, is independently H, a silane        radical of the formula —[R⁶R⁷Si]_(k)[R⁶R⁷SiH] (wherein R⁶, R⁷        are independently a H or a C₁ to C₃₀ hydrocarbyl free of        aliphatic unsaturation, k is an integer from 0 to 10) or a C₁ to        C₃₀ hydrocarbyl free of aliphatic unsaturation,    -   wherein the subscripts a, b, c, d, and e represent the mole        fraction of each siloxy unit present and range as follows:        -   a is about 0 to about 0.6,        -   b is about 0 to about 0.6,        -   c is about 0 to about 1,        -   d is about 0 to about 1,        -   e is about 0 to about 0.6,    -   with the provisos that:        -   b+c+d+e>0 and a+b+c+d+e≦1, and        -   at least about 1 mole % (e.g., at least about 5 mole %, at            least about 10 mole %, at least about 15 mole % or at least            about 20 mole %; or from about 1 to about 20 mole %, about 1            to about 10 mole % or about 1 to about 5 mole %) of R¹            and/or R² are H or a silane radical of the formula            —[R⁶R⁷Si]_(k)[R⁶R⁷SiH].

In one embodiment, compounds having the unit formula [R¹₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e)are compounds of the formula R¹ _(q)R³ _((3-q))SiO(R¹₂SiO_(2/2))_(m)SiR³ _((3-q))R¹ _(q), where each R¹, at each occurrence,is independently a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation;m is from 0 to 50 (e.g., about 10 to about 50 D units; about 20 to about50 D units; about 5 to about 40 D units; or about 10 to about 40 Dunits), alternatively 0 to 10, alternatively 0 to 5, alternatively m is0; q is 0, 1, or 2, alternatively q is 2, and each R₃, at eachoccurrence, is independently H or R¹, with the proviso that at least oneR₃ at each terminus of the compound of the formula R¹ _(q)R³_((3-q))SiO(R¹ ₂SiO_(2/2))_(m)SiR³ _((3-q))R¹ _(q). is H.

In some embodiments, the compounds having unit formula [R¹₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e)or the compounds of the formula R¹ _(q)R³ _((3-q))SiO(R¹₂SiO_(2/2))_(m)SiR³ _((3-q))R¹ _(q) have the formulaH(CH₃)₂SiO[(CH₃)₂SiO_(2/2))]_(n)Si(CH₃)₂H, where n may vary from 10 to400 (e.g., an average of from about 10 to about 350 D units; about 10 toabout 300 D units; about 10 to about 200 D units; about 10 to about 100D units; about 50 to about 400 D units; about 100 to about 400 D units;about 150 to about 400 D units; about 200 to about 400 D units; about300 to about 400 D units; about 50 to about 300 D units; about 100 toabout 300 D units; about 150 to about 300 D units; about 200 to about300 D units; about 100 to about 150 D units, about 115 to about 125 Dunits, about 90 to about 170 D units or about 110 to about 140 D units.

In a further embodiment, the compounds having unit formula [R¹₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e)or the compounds of the formula R¹ _(q)R³ _((3-q))SiO(R¹₂SiO_(2/2))_(m)SiR³ _((3-q))R¹ _(q) have the formulaH(CH₃)₂SiOSi(CH₃)₂H, H(CH₃)(Ph)SiOSi(CH₃)₂H, H(Ph)₂SiOSi(CH₃)₂H,H(CH₃)(Ph)SiOSi(CH₃)(Ph)H, H(Ph)₂SiOSi(Ph)₂H,H(CH₃)₂SiOSi(CH₃)₂OSi(CH₃)₂H, H(CH₃)₂SiOSi(Ph)(CH₃)OSi(CH₃)₂H,H(CH₃)₂SiOSi(Ph)₂OSi(CH₃)₂H, H(CH₃)(Ph)SiOSi(Ph)(CH₃)OSi(Ph)(CH₃)H,H(CH₃)(Ph)SiOSi(Ph)₂OSi(Ph)(CH₃)H orH(CH₃)₂SiOSi(Ph)₂OSi(Ph)₂OSi(CH₃)₂H.

In other embodiments, the curable compositions may be cured via ahydrosilylation reaction in the presence of a compound having unitformula:[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)[R¹SiO_(3/2)]_(h)

wherein R¹ and R² are independently a C₁ to C₃₀ hydrocarbyl free ofaliphatic unsaturation, R⁸ and R⁹ are independently a H, a C₁ to C₃₀hydrocarbyl free of aliphatic unsaturation or a silane radical of theformula —[R¹⁰R¹¹Si]_(p)[R¹⁰R¹¹SiH] (wherein R¹⁰, R¹¹ is independently aH or a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation, p is aninteger from 0 to 10), f is an integer from 0 to 100 (e.g., from 2 to100, 40 to 50, 40 to 60, 50 to 70, 40 to 80, 40 to 70, 1 to 80, 1 to 10,0 to 10, 1 to 6 or 10 to 70), g is an integer from 0 to 50 (e.g., from 1to 50, 1 to 30, 1 to 8, 1 to 6 or 1 to 4), h is an integer from 0 to 60(e.g., from 30 to 50, 0 to 15, 0 to 40, 10 to 40, 20 to 40, 0 to 10, 0to 5 or 1 to 5), and the number of SiH groups in the compound havingunit formula [R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)[R¹SiO_(3/2)]_(h)is ≧2 per molecule (e.g., ≧4, ≧6, ≧8, ≧10; or from 2 to 10 permolecule).

Non-limiting examples of compounds having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)[R¹SiO_(3/2)]_(h) wherein g is 0include:[R¹R²R⁸SiO_(1/2)]_(f)[R¹SiO_(3/2)]_(h)wherein R¹ and R² is independently a C₁ to C₃₀ hydrocarbyl free ofaliphatic unsaturation, R⁸ is independently a H, a C₁ to C₃₀ hydrocarbylfree of aliphatic unsaturation or a silane radical of the formula—[R¹⁰R¹¹Si]_(p)[R¹⁰R¹¹SiH] (wherein R¹⁰, R¹¹ is independently a H or aC₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation, p is an integerfrom 0 to 10), f is an integer from 2 to 100 (e.g., from 40 to 50, 40 to60, 50 to 70, 40 to 80, 40 to 70, 2 to 80, 2 to 10, 2 to 6 or 10 to 70),h is an integer from 0 to 60 (e.g., from 30 to 50, 0 to 15, 0 to 40, 10to 40, 20 to 40, 0 to 10, 0 to 5 or 1 to 5), and the number of SiHgroups in the compound having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹SiO_(3/2)]_(h) is ≧2 per molecule (e.g., ≧4, ≧6,≧8, 10; or from 2 to 10 per molecule).

Other non-limiting examples of compounds having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)[R¹SiO_(3/2)]_(h) wherein g is 0include:[R¹R²R⁸SiO_(1/2)]_(f)[R¹SiO_(3/2)]_(h)wherein R¹ and R² is independently C₁ to C₁₀ alkyl (e.g., C₁ to C₈alkyl, C₁ to C₅ alkyl or C₁ to C₃ alkyl) or C₆ to C₁₄ aryl (e.g., C₆ toC₁₀ aryl), R⁸ is independently a H or a C₁ to C₁₀ alkyl (e.g., C₁ to C₈alkyl, C₁ to C₅ alkyl or C₁ to C₃ alkyl) or C₆ to C₁₄ aryl (e.g., C₆ toC₁₀ aryl), f is an integer from 2 to 100 (e.g., from 40 to 50, 40 to 60,50 to 70, 40 to 80, 40 to 70, 2 to 80, 2 to 10, 2 to 6 or 10 to 70), his an integer from 0 to 60 (e.g., from 30 to 50, 0 to 15, 0 to 40, 10 to40, 20 to 40, 0 to 10, 0 to 5 or 1 to 5), and at least two R⁸ are H,such that the number of SiH groups in the compound having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹SiO_(3/2)]_(h) is ≧2 per molecule (e.g., ≧4, ≧6,≧8, ≧10; or from 2 to 10 per molecule).

Still other non-limiting examples of compounds having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)[R¹SiO_(3/2)]_(h) wherein g is 0include:[R¹R²R⁸SiO_(1/2)]_(f)[R¹SiO_(3/2)]_(h)wherein R¹ and R² is independently C₁ to C₃ alkyl or C₆ to C₁₀ aryl, R⁸is independently a H, C₁ to C₃ alkyl or C₆ to C₁₀ aryl, f is an integerfrom 2 to 100 (e.g., from 40 to 50, 40 to 60, 50 to 70, 40 to 80, 40 to70, 2 to 80, 2 to 10, 2 to 6 or 10 to 70), h is an integer from 0 to 60(e.g., from 30 to 50, 0 to 15, 0 to 40, 10 to 40, 20 to 40, 0 to 10, 0to 5 or 1 to 5), and at least two R⁸ are H, such that the number of SiHgroups in the compound having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹SiO_(3/2)]_(h) is ≧2 per molecule (e.g., ≧4, ≧6,≧8, ≧10; or from 2 to 10 per molecule).

Yet other non-limiting examples of compounds having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)[R¹SiO_(3/2)]_(h) wherein g is 0include:[R¹R²R⁸SiO_(1/2)]_(f)[R¹SiO_(3/2)]_(h)wherein R¹ is methyl or phenyl; R² is methyl or phenyl; R⁸ is H, f is aninteger from 2 to 100 (e.g., from 40 to 50, 40 to 60, 50 to 70, 40 to80, 40 to 70, 2 to 80, 2 to 10, 2 to 6 or 10 to 70), h is an integerfrom 0 to 60 (e.g., from 30 to 50, 0 to 15, 0 to 40, 10 to 40, 20 to 40,0 to 10, 0 to 5 or 1 to 5), such that the number of SiH groups in thecrosslinker is ≧2 per crosslinker molecule (e.g., ≧4, ≧6, ≧8, ≧10; orfrom 2 to 10 per crosslinker molecule). Or, in some embodiments, R¹ ismethyl or phenyl; R² is methyl or phenyl; R⁸ is H, e is an integer from40 to 80 (e.g., from 40 to 50, 40 to 60 or 50 to 70), g is an integerfrom 30 to 60, such that the number of SiH groups in the compound havingunit formula [R¹R²R⁸SiO_(1/2)]_(f)[R¹SiO_(3/2)]_(h) is ≧2 per molecule(e.g., ≧4, ≧6, ≧8, ≧10; or from 2 to 10 per molecule).

Non-limiting examples of compounds having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)[R¹SiO_(3/2)]_(h) wherein h is0:[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)wherein R¹ and R² are independently a C₁ to C₃₀ hydrocarbyl free ofaliphatic unsaturation, R⁸ and R⁹ are independently a H, a C₁ to C₃₀hydrocarbyl free of aliphatic unsaturation or a silane radical of theformula —[R¹⁰R¹¹Si]_(p)[R¹⁰R¹¹SiH] (wherein R¹⁰, R¹¹ is independently aH or a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation, p is aninteger from 0 to 10), f is an integer from 0 to 10 (e.g., from 0 to 9,1 to 9, 2 to 8, 2 to 6 or 2 to 4), g is an integer from 0 to 10 (e.g.,from 0 to 9, from 0 to 7, from 0 to 5, from 1 to 8, 1 to 6 or 1 to 4),and the number of SiH groups in the compound having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g) is ≧2 per molecule (e.g., ≧4,≧6, ≧8, ≧10; or from 2 to 10 per molecule).

Other non-limiting examples of compounds having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)[R¹SiO_(3/2)]_(h) wherein h is0:[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)wherein R¹, R², and R⁹ is independently C₁ to C₁₀ alkyl (e.g., C₁ to C₈alkyl, C₁ to C₅ alkyl or C₁ to C₃ alkyl) or C₆ to C₁₄ aryl (e.g., C₆ toC₁₀ aryl), R⁸ is independently a H or a C₁ to C₁₀ alkyl (e.g., C₁ to C₈alkyl, C₁ to C₅ alkyl or C₁ to C₃ alkyl) or C₆ to C₁₄ aryl (e.g., C₆ toC₁₀ aryl), f is an integer from 2 to 10 (e.g., from 2 to 8, 2 to 6 or 2to 4), g is an integer from 0 to 10 (e.g., from 1 to 8, 1 to 6 or 1 to4), and at least two R⁸ are H such that the number of SiH groups in thecompound having unit formula [R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g) is≧2 per molecule (e.g., ≧4, ≧6, ≧8, ≧10; or from 2 to 10 per molecule).

Still other non-limiting examples of compounds having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)[R¹SiO_(3/2)]_(h) wherein h is0:[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)wherein R¹, R², and R⁹ is independently C₁ to C₃ alkyl or C₆ to C₁₀aryl, R⁸ is independently a H, C₁ to C₃ alkyl or C₆ to C₁₀ aryl, f is aninteger from 2 to 10 (e.g., from 2 to 8, 2 to 6 or 2 to 4), g is aninteger from 0 to 10 (e.g., from 0 to 9, from 0 to 7, from 0 to 5, from1 to 8, 1 to 6 or 1 to 4), and at least two R⁸ are H such that thenumber of SiH groups in the compound having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g) is ≧2 per molecule (e.g., ≧4,≧6, ≧8, ≧10; or from 2 to 10 per molecule).

Yet other non-limiting examples of compounds having unit formula[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)[R¹SiO_(3/2)]_(h) wherein h is0:[R¹R²R⁸SiO_(1/2)]_(f)[R¹R⁹SiO_(2/2)]_(g)wherein R¹ is methyl or phenyl; R² is methyl or phenyl; R⁹ is R² ismethyl or phenyl; R⁸ is H, f is an integer from 2 to 10 (e.g., from 2 to8, 2 to 6 or 2 to 4), and g is an integer from 1 to 10 (e.g., from 1 to8, 1 to 6 or 1 to 4). Or, in some embodiments, R¹ is methyl or phenyl;R² is methyl or phenyl; R⁹ is R² is methyl or phenyl; R⁸ is H, f is aninteger from 2 to 10 (e.g., from 2 to 8, 2 to 6 or 2 to 4), and g is aninteger from 0 to 10 (e.g., from 0 to 9, from 0 to 7, from 0 to 5, from1 to 8, 1 to 6 or 1 to 4).

In some embodiments, a combination of compounds of the formula[R¹R²R⁸SiO_(1/2)]f[R¹R⁹SiO_(2/2)]_(g) and[R¹R²R⁸SiO_(1/2)]_(f)[R¹SiO_(3/2)]_(h) (e.g., M^(H) ₂D^(Ph) ₂ and M^(H)₆₀T^(Ph) ₄₀, respectively) is used in the curable compositions of thevarious embodiments of the present invention. When a combination of twodifferent compounds of the formula[R¹R²R⁸SiO_(1/2)]_(e)[R¹R⁹SiO_(2/2)]_(f) and[R¹R²R⁸SiO_(1/2)]_(e)[R¹SiO_(3/2)]_(g) is used, the compounds can beused in any suitable amount and in any suitable ratio. In some examples,a suitable w/w ratio of the two different compounds of the formula[R¹R²R⁸SiO_(1/2)]_(e)[R¹R⁹SiO_(2/2)]_(f) and[R¹R²R⁸SiO_(1/2)]_(e)[R¹SiO_(3/2)]_(g) is from about 8:1 to about 1:8(e.g., from about 6:1 to about 1:1, about 5:1 to about 1:1; about 5:1 toabout 2:1; or about 5:1 to about 3:1 w/w).

The hydrosilylation reaction may be conducted under any suitableconditions known in the art for effecting hydrosilylation reactions.

The curable compositions may contain a hydrosilylation catalyst. Thehydrosilylation catalyst may be any suitable hydrosilylation catalyst,including, Group VIII metal based catalyst selected from a platinum,rhodium, iridium, palladium, ruthenium or iron. Group VIII group metalcontaining catalysts useful to catalyze the hydrosilylation reaction canbe any catalyst known to catalyze reactions of silicon bonded hydrogenatoms with silicon bonded moieties comprising unsaturated hydrocarbongroups. In some embodiments, the Group VIII metal for use as a catalystto effect the hydrosilylation is a platinum based catalyst such asplatinum metal, platinum compounds and platinum complexes.

Suitable platinum catalysts include, but are not limited to, thecatalyst described in U.S. Pat. No. 2,823,218 (e.g., “Speier'scatalyst”) and U.S. Pat. No. 3,923,705, the entireties of both of whichare incorporated by reference as if fully set forth herein. Othersuitable platinum catalysts include, but are not limited to, theplatinum catalyst referred to as “Karstedt's catalyst,” which aredescribed in U.S. Pat. Nos. 3,715,334 and 3,814,730. Karstedt's catalystis a platinum divinyl tetramethyl disiloxane complex, in some cases,containing about one-weight percent of platinum in a solvent such astoluene. Alternatively platinum catalysts include, but are not limitedto, the reaction product of chloroplatinic acid and an organosiliconcompound containing terminal aliphatic unsaturation, including thecatalysts described in U.S. Pat. No. 3,419,593, the entirety of which isincorporated by reference as if fully set forth herein. Alternatively,hydrosilyation catalysts include, but are not limited to, neutralizedcomplexes of platinum chloride and divinyl tetramethyl disiloxane, asdescribed in U.S. Pat. No. 5,175,325. Further suitable hydrosilylationcatalysts are described in, for example, U.S. Pat. Nos. 3,159,601;3,220,972; 3,296,291; 3,516,946; 3,989,668; 4,784,879; 5,036,117; and5,175,325 and EP 0 347 895 B1.

The hydrosilylation catalyst may be added in an amount equivalent to aslittle as 0.001 parts by weight of elemental platinum group metal, perone million parts (ppm) of the total reaction composition. In someembodiments, the concentration of the hydrosilylation catalyst ascompared to the solids of the the reaction composition is theconcentration capable of providing the equivalent of at least 1 part permillion of elemental platinum group metal. A catalyst concentrationproviding the equivalent of 1 to 500, alternatively 50 to 500,alternatively 50 to 200 parts per million of elemental platinum groupmetal may be used.

The present disclosure also provides curable compositions comprisingresin linear organosiloxane block copolymers comprising, among otherthings, from about 0.5 to about 5 mole % C₁ to C₃₀ hydrocarbyl groupcomprising at least one aliphatic unsaturated bond, wherein the curablecompositions have a cure speed in Pa/min (the slope of the storagemodulus, G′, as a function of time, as determined from rheologymeasuring the increase in G′ as a function of temperature) of at leastabout 1 Pa/min, at least about 2 Pa/min, at least about 4 Pa/min, atleast about 10 Pa/min or at least about 20 Pa/min at a heating rate of5° C./min, e.g., from about 1 Pa/min to about 10 Pa/min, from about 1Pa/min to about 20 Pa/min, from about 1 Pa/min to about 6 Pa/min, fromabout 2 Pa/min to about 6 Pa/min, from about 1 Pa/min to about 100Pa/min, from about 5 Pa/min to about 50 Pa/min; from about 10 Pa/min toabout 100 Pa/min; from about 20 Pa/min to about 80 Pa/min; from about 20Pa/min to about 60 Pa/min; from about 50 Pa/min to about 100 Pa/min; orfrom about 30 Pa/min to about 90 Pa/min at a heating rate of 5° C./min.

Solid Resin-Linear Organosiloxane Block Copolymer Compositions

Solid compositions containing the resin-linear organosiloxane blockcopolymers of the embodiments of the present invention, may be preparedby removing some or substantially all the solvent from the curableorganosiloxane block copolymer compositions as described herein. Thesolvent may be removed by any known processing techniques. In oneembodiment, a film of the curable compositions containing theorganosiloxane block copolymers is formed, and the solvent is allowed toevaporate from the film. Subjecting the films to elevated temperatures,and/or reduced pressures, may accelerate solvent removal and subsequentformation of the solid curable composition. Alternatively, the curablecompositions may be passed through an extruder to remove solvent andprovide the solid composition in the form of a ribbon or pellets.Coating operations against a release film could also be used as in slotdie coating, knife over roll, rod, or gravure coating. Also,roll-to-roll coating operations could be used to prepare a solid film.In coating operations, a conveyer oven or other means of heating andevacuating the solution can be used to drive off the solvent and obtainthe final solid film.

Although not wishing to be bound by any theory, it is possible that thestructural ordering of the disiloxy and trisiloxy units in theorganosiloxane block copolymer, as described herein, may provide thecopolymer with certain unique physical property characteristics whensolid compositions of the block copolymer are formed. For example, thestructural ordering of the disiloxy and trisiloxy units in the copolymermay provide solid coatings that allow for a high optical transmittanceof visible light (e.g., at wavelengths above 350 nm). The structuralordering may also allow the organosiloxane block copolymer to flow andcure upon heating, yet remain stable at room temperature. They may alsobe processed using lamination techniques. These properties are useful toprovide coatings for various electronic articles to improve weatherresistance and durability, while providing low cost and easy proceduresthat are energy efficient. Finally, the structural ordering of thedisiloxy and trisiloxy units in the copolymer may influence, among otherthings, the glass transition temperature T_(g), such that the copolymerhas a high T_(g) phase; the tack such that the copolymer has low tack;the strength of the copolymer, as evidenced by, among other things, thetensile strength; and shelf stability.

In some embodiments, the aforementioned organosiloxane block copolymersare isolated in a solid form, for example by casting films of a solutionof the block copolymer in an organic solvent (e.g., benzene, toluene,xylene or combinations thereof) and allowing the solvent to evaporate.Under these conditions, the aforementioned organosiloxane blockcopolymers can be provided as solutions in an organic solvent containingfrom about 50 wt % to about 80 wt % solids, e.g., from about 60 wt % toabout 80 wt %, from about 70 wt % to about 80 wt % or from about 75 wt %to about 80 wt % solids. In some embodiments, the solvent is toluene. Insome embodiments, such solutions may have a viscosity of from about 1500cSt to about 10000 cSt at 25° C., e.g., from about 1500 cSt to about3000 cSt, from about 2000 cSt to about 4000 cSt, from about 2000 cSt toabout 3000 cSt, from about 2000 cSt to about 8000 cSt, from about 5000cSt to about 10000 cSt or from about 8000 cSt to about 10000 cSt at 25°C.

In some embodiments, the cured product of the curable compositionscontaining the resin-linear organosiloxane block copolymers of theembodiments of the present invention has a Young's modulus after agingfor 50 hours at 225° C. that is not substantially different from theYoung's modulus before aging for 50 hours at 225° C. In someembodiments, the ratio of the Young's Modulus after aging for 50 hoursat 225° C. to the Young's modulus before aging is 3 or less (e.g., about2.5 or less, about 2.0 or less, or about 1.5 or less; or about 1 toabout 2.5, from about 1.25 to about 2, from about 1.5 to about 1.8 orfrom about 1.4 to about 2.25 after aging, it being understood that ifthe ratio is 1, the Young's modulus before and after aging is the same).

In some embodiments, the cured product of the curable compositionscontaining the resin-linear organosiloxane block copolymers of theembodiments of the present invention has a Young's modulus after agingfor 30 hours at 225° C. that is not substantially different from theYoung's modulus before aging for 30 hours at 225° C. In someembodiments, the Young's Modulus after aging for 30 hours at 225° C.compared to the Young's modulus before aging is 1.5 or less (e.g., about1.4 or less, about 1.3 or less, or about 1.2 or less after aging; orfrom about 0 to about 1.5, from about 0.5 to about 1.5, from about 1.0to about 1.5, or from about 1.0 to about 1.5 after aging, it beingunderstood that if the ratio is 1, the Young's modulus before and afteraging is the same).

In some embodiments, the cured product of the curable compositionscontaining the resin-linear organosiloxane block copolymers of theembodiments of the present invention has a Young's Modulus before agingfor 30 or 50 hours at 225° C. of from about 70 MPa to about 200 MPabefore aging (e.g., from about 70 MPa to 100 MPa, from about 100 MPa toabout 150 MPa, from about 120 MPa to about 180 MPa, from about 150 MPato about 180 MPa or from about 130 MPa to about 180 MPa).

In some embodiments, the Young's modulus after aging for 30 hours at225° C. does not change substantially. If the Young's modulus doeschange after aging for 30 hours at 225° C., the Young's modulus afteraging is from about 100 MPa to about 250 MPa (e.g., from about 100 MPato about 150 MPa, from about 150 MPa to about 180 MPa, from about 130MPa to 180 MPa, from about 100 MPa to about 140 MPa or from about 140MPa to about 180 MPa) after aging for 30 hours at 225° C.

In some embodiments, the Young's modulus after aging for 50 hours at225° C. does not change substantially. If the Young's modulus doeschange after aging for 50 hours at 225° C., the Young's modulus afteraging is from about 130 MPa to about 250 MPa (e.g., from about 130 MPato about 200 MPa, from about 150 MPa to about 250 MPa, from about 180MPa to 240 MPa, from about 150 MPa to about 240 MPa or from about 180MPa to about 250 MPa) after aging for 50 hours at 225° C.

In some embodiments, the cured product of the curable compositionscontaining the resin-linear organosiloxane block copolymers of theembodiments of the present invention may be cured in the absence of acondensation catalyst. In other embodiments, the cured product of thecurable compositions containing the resin-linear organosiloxane blockcopolymers of the embodiments of the present invention the product curesand is cured in the presence of a phosphor or a filler. Representativeexamples of suitable phosphors and fillers may be found in PCT Appl. No.PCT/US2013/031253.

Upon drying or forming a solid, the non-linear blocks of the blockcopolymer further aggregate together to form “nano-domains.” As usedherein, “predominately aggregated” means the majority (e.g., greaterthan 50%; greater than 60%; greater than 75%, greater than 80%, greaterthan 90%; from about 75% to about 90%, from about 80% to about 90%, orfrom about 75% to about 85%) of the non-linear blocks of theorganosiloxane block copolymer are found in certain regions of the solidcomposition, described herein as “nano-domains.” As used herein,“nano-domains” refers to those phase regions within the solid blockcopolymer compositions that are phase separated within the solid blockcopolymer compositions and possess at least one dimension sized from 1to 100 nanometers. The nano-domains may vary in shape, providing atleast one dimension of the nano-domain is sized from 1 to 100nanometers. Thus, the nano-domains may be regular or irregularly shaped.The nano-domains may be spherically shaped, tubular shaped, and, in someinstances, lamellar shaped.

In a further embodiment, the solid organosiloxane block copolymers asdescribed herein contain a first phase and an incompatible second phase,the first phase containing predominately the disiloxy units [R¹₂SiO_(2/2)] as defined herein, the second phase containing predominatelythe trisiloxy units [R²SiO_(3/2)] as defined herein, the non-linearblocks being sufficiently aggregated into nano-domains which areincompatible with the first phase.

In some embodiments, the resin-linear organosiloxane block copolymers ofthe embodiments of the present invention may contain an organosiloxaneresin (e.g., free resin that is not part of the block copolymer). Inthis example, the organosiloxane resin also predominately aggregateswithin the nano-domains. In some embodiments, the free resin is presentin an amount of from about 5 to about 30 wt. %, preferably from about 10to about 30 wt. %.

The structural ordering of the disiloxy and trisiloxy units in the solidblock copolymers of the present disclosure, and characterization of thenano-domains, may be determined explicitly using certain analyticaltechniques such as Transmission Electron Microscopic (TEM) techniques,Atomic Force Microscopy (AFM), Small Angle Neutron Scattering, SmallAngle X-Ray Scattering, and Scanning Electron Microscopy.

Alternatively, the structural ordering of the disiloxy and trisiloxyunits in the block copolymer, and formation of nano-domains, may beimplied by characterizing certain physical properties of coatingsresulting from the present organosiloxane block copolymers. For example,the present organosiloxane copolymers may provide coatings that have anoptical transmittance of visible light greater than 95%. One skilled inthe art recognizes that such optical clarity is possible (other thanrefractive index matching of the two phases) only when visible light isable to pass thorough such a medium and not be diffracted by particles(or domains as used herein) having a size greater than 150 nanometers.As the particle size, or domains further decreases, the optical claritymay be further improved. Thus, coatings or encapsulants derived from thepresent organosiloxane copolymers may have an optical transmittance ofvisible light of at least 95%, e.g., at least 96%; at least 97%; atleast 98%; at least 99%; or 100% transmittance of visible light at acoating or encapsulant or film film thickness of 0.5 mm or greater. Asused herein, the term “visible light” includes light with wavelengthsabove 350 nm.

Some of the embodiments of the present invention relate to opticalassemblies and articles comprising the compositions described hereinsuch as those described in Published PCT Application Nos. WO2013/101674,filed Dec. 20, 2012; WO2013/109607, filed Jan. 16, 2013; andWO2013/119796, filed Feb. 7, 2013, all of which are incorporated byreference as if fully set forth herein. Accordingly, some embodiments ofthe present invention relate to an LED encapsulant comprising anorganosiloxane block copolymer described herein.

The term “about,” as used herein, can allow for a degree of variabilityin a value or range, for example, within 10%, within 5%, or within 1% ofa stated value or of a stated limit of a range.

Values expressed in a range format should be interpreted in a flexiblemanner to include not only the numerical values explicitly recited asthe limits of the range, but also to include all the individualnumerical values or sub-ranges encompassed within that range as if eachnumerical value and sub-range were explicitly recited. For example, arange of “about 0.1% to about 5%” or “about 0.1% to 5%” should beinterpreted to include not just about 0.1% to about 5%, but also theindividual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g.,0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range.

Embodiments of the invention described and claimed herein are not to belimited in scope by the specific embodiments herein disclosed, sincethese embodiments are intended as illustration of several aspects of thedisclosure. Any equivalent embodiments are intended to be within thescope of this disclosure. Indeed, various modifications of theembodiments in addition to those shown and described herein will becomeapparent to those skilled in the art from the foregoing description.Such modifications are also intended to fall within the scope of theappended claims.

The Abstract is provided to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims.

EXAMPLES

The following examples are included to demonstrate specific embodimentsof the invention. However, those of skill in the art should, in light ofthe present disclosure, appreciate that many changes can be made in thespecific embodiments which are disclosed and still obtain a like orsimilar result without departing from the spirit and scope of theinvention. All percentages are in wt %. All measurements were conductedat 23° C. unless indicated otherwise.

Example 1: Representative Preparation of Resin-Linear (RL) BlockCopolymers

A 12 L 3-neck round bottom flask was charged with phenyl-T resin (1800g, 13.18 moles Si, Dow Corning 217 flake) and toluene (1482 g) undernitrogen. The flask was equipped with a thermometer, Teflon stir paddle,and a Dean Stark apparatus attached to a water-cooled condenser (DeanStark was prefilled with toluene). The reaction mixture was heated atreflux for 30 minutes with 8.18 g water removed. The reaction solutionwas cooled to 108° C., followed by quickly adding MTA/ETA(methyltriacetoxysilane/ethyltriacetoxysilane) capped silanol terminatedPhMe siloxane (which was synthesized by adding 50/50 wt % MTA/ETA(methyltriacetoxysilane/ethyltriacetoxysilane) (46.96 g, 0.207 moles Si)to the siloxane (2200 g, 16.13 moles Si, DP=127; wherein “DP” stands fordegree of polymerization as determined from NMR) and stirring them atroom temperature in a glove box for 1 hour). The reaction mixture washeated at reflux for 2 hours under nitrogen with 14.66 g water removed.The reaction solution was cooled to 108° C. again and charged with 50/50wt % MTA/ETA (methyltriacetoxysilane/ethyltriacetoxysilane) (314.49 g,1.348 moles), followed by refluxing for 1 hour with 0.56 g waterremoved, and then the reaction mixture was cooled to 90° C. and addedwith deionized (DI) water (430 g), followed by refluxing to remove watervia azeotropic distillation. The adding-removing water process wasrepeated two times with a total 1045.9 g aqueous phase removed. Finallythe solid content of the solution was increased to about 70 wt. % bydistilling and removing some volatiles (1331.4 g) at 118° C. Thesynthesized RL solution was clear and colorless, and stored at roomtemperature for future use.

Example 2: Preparation of M^(Vi) Resin-Linear Block Copolymers Having3.5 Mole % Vi

A 1 L dry 3-neck round bottom flask was charged with a solution of theresin-linear block copolymer made according to Example 1 (100 g, 0.77moles Si, 0.138 moles silanol) in toluene (150 g) and triethylamine(TEA, 5.76 mL, 0.0414 moles) under nitrogen, followed by stirring for 10minutes. Vinyldimethylchlorosilane (5.7 mL, 0.0414 moles) was slowlyadded to the flask by a syringe within 10 minutes. White saltprecipitates were formed within 1 minute after adding the chlorosilane.The reaction mixture was stirred under nitrogen and room temperature for3 hours, followed by adding 1 mL DI water to quenching the unreactedchlorosilane. Finally 5 g anhydrous Na₂SO₄ was added to the flask,followed by stirring under air overnight to completely dry the solution.In second day, the reaction solution was filtered with 1.2 μm filterpaper under 20 psi to remove the white salt precipitates. The solventand small amount of TEA and quenched vinyl precursors were removedcompletely by using Rotavapor at 80° C. and 5 mm Hg vacuum. The M^(Vi)RLproduct is soft colorless gum-like materials containing 3.5 mole % Viand can re-dissolve in toluene.

Example 3: Preparation of M^(Vi)-Modified Resin-Linear Block PolymersHaving 2 Mole % Vi

(i) Preparation of M^(Vi) _(0.045)T^(Ph) _(0.955) resin: A 3 L 3-neckround bottom flask was loaded DI water (1011.9 g), followed by coolingto 4° C. with ice-water bath. The flask was equipped with a thermometer,Teflon stir paddle, and a water-cooled condenser. A pre-mixed solutionof phenyltrichlorosilane (500.5 g, 2.366 moles),vinyldimethylchlorosilane (15.03 g, 0.125 moles) and toluene (494.4 g)was added to the cooled water within 2 minutes, followed by stirring for5 minutes with the removal of ice-water bath (the maximum temperature ofthe solution was up to 74° C. during the reaction). The reaction mixturewas transferred into a 2 L round bottom flask with a bottom drain andthen the aqueous layer was removed. DI water (82.4 g) was added to theremained materials, followed by heating at 80° C. for 10 minutes andthen cooling down and removing the aqueous phase. The remained materialswas added by a mixture of 2-propanol (20.6 g) and DI water (61.8 g),followed by heating at 80° C. for 10 minutes and removing aqueous phase,repeating this step for several times until the final wash water phasehad a pH of 4.0. The reaction mixture was then heated at reflux toremove residual water via azeotropic distillation. The synthesizedM^(Vi) _(0.045)T^(Ph) _(0.955) resin was dried by using a rotavapor at120° C. The M^(Vi) _(0.045)T^(Ph) _(0.955) product was a “crunchy” solidat room temperature with the yield of 314 g, containing 4.5 mole % Vi.

(ii) Preparation of M^(Vi)RLs (2 mole % Vi): A 500 mL 4-neck roundbottom flask was charged with M^(Vi) _(0.045)T^(Ph) _(0.955) resin (72g, 0.541 moles Si) and toluene (59.3 g) under nitrogen. The flask wasequipped with a thermometer, Teflon stir paddle, and a Dean Starkapparatus attached to a water-cooled condenser (Dean Stark was prefilledwith toluene). The reaction mixture was heated at reflux for 30 minuteswith 0.01 g water removed. The reaction solution was cooled to 108° C.,followed by quickly adding MTA/ETA(methyltriacetoxysilane/ethyltriacetoxysilane) capped silanol terminatedPhMe siloxane (which was synthesized by adding MTA/ETA (50/50, 1.85 g,0.00813 moles Si) to the siloxane (88 g, 0.645 moles Si, DP=129) andstirring them at room temperature in a glove box for 1 hour). Thereaction mixture was heated at reflux for 2 hours under nitrogen with0.65 g water removed. The reaction solution was cooled to 108° C. againand charged with MTA/ETA (50/50, 4.92 g, 0.0216 moles Si), followed byrefluxing for 1 hour with 0.25 g water removed, and then the reactionmixture was cooled to 90° C. and added with DI water (8.05 g), followedby refluxing to remove water via azeotropic distillation. Theadding-removing water was repeated three times. Finally the solidcontent of the solution was increased to about 70 wt. % by distillingand removing some volatiles (39.2 g) at 118° C. The synthesizedM^(Vi)RLs solution was clear and colorless, and contains 2 mole % Vi.

Example 4: Preparation of M^(Vi)-Modified Resin-Linear Block PolymersHaving 3.7 Mole % Vi

(i) Preparation of M^(Vi) _(0.078)T^(Ph) _(0.922) resin: A 3 L 3-neckround bottom flask was loaded DI water (1011.9 g), followed by coolingto 4° C. with ice-water bath. The flask was equipped with a thermometer,Teflon stir paddle, and a water-cooled condenser. A pre-mixed solutionof phenyltrichlorosilane (500.5 g, 2.366 moles),vinyldimethylchlorosilane (26.55 g, 0.22 moles) and toluene (508.5 g)was added to the cooled water within 2 minutes, followed by stirring for5 minutes with the removal of ice-water bath (the maximum temperature ofthe solution was up to 71° C. during the reaction). The reaction mixturewas transferred into a 2 L round bottom flask with a bottom drain andthen the aqueous layer was removed. DI water (84.8 g) was added to theremained materials, followed by heating at 80° C. for 10 minutes andthen cooling down and removing the aqueous phase. The remained materialswas added by a mixture of 2-propanol (21.2 g) and DI water (63.6 g),followed by heating at 80° C. for 10 minutes and removing aqueous phase,repeating this step for several times until the final wash water phasehad a pH of 4.0. The reaction mixture was then heated at reflux toremove residual water via azeotropic distillation. The synthesizedM^(Vi)T^(Ph) resin was dried by using a rotavapor at 120° C. The productwas a crunchy solid at room temperature with the yield of 332 g,containing 7.8 mole % Vi.

(ii) Preparation of M^(Vi)RLs (3.7 mole % Vi): A 500 mL 4-neck roundbottom flask was charged with M^(Vi) _(0.078)T^(Ph) _(0.922) resin (72g, 0.547 moles Si) and toluene (59.3 g) under nitrogen. The flask wasequipped with a thermometer, Teflon stir paddle, and a Dean Starkapparatus attached to a water-cooled condenser (Dean Stark was prefilledwith toluene). The reaction mixture was heated at reflux for 30 minuteswith 0.05 g water removed. The reaction solution was cooled to 108° C.,followed by quickly adding MTA/ETA capped silanol terminated PhMesiloxane (which was synthesized by adding MTA/ETA (50/50, 1.85 g,0.00813 moles Si) to the siloxane (88 g, 0.645 moles Si, DP=129) andstirring them at room temperature in a glove box for 1 hour. Thereaction mixture was heated at reflux for 2 hours under nitrogen with0.7 g water removed. The reaction solution was cooled to 108° C. againand charged with MTA/ETA (50/50, 4.98 g, 0.0219 moles Si), followed byrefluxing for 1 hour with 0.3 g water removed, and then the reactionmixture was cooled to 90° C. and added with DI water (8.12 g), followedby refluxing to remove water via azeotropic distillation. Theadding-removing water was repeated for three times. Finally the solidcontent of the solution was increased to about 70 wt. % by distillingand removing some volatiles (38.4 g) at 118° C. The synthesizedM^(Vi)RLs solution was clear and colorless, and contains 3.7 mole % Vi.

Example 5: Preparation of D^(Vi)-Modified Resin-Linear Block PolymersHaving 3.7 Mole % Vi

(i) Preparation of D^(Vi) _(0.08)T^(Ph) _(0.92) resin: A 3 L 3-neckround bottom flask was loaded DI water (1011.9 g), followed by coolingto 4° C. with ice-water bath. The flask was equipped with a thermometer,Teflon stir paddle, and a water-cooled condenser. A pre-mixed solutionof phenyltrichlorosilane (500.5 g, 2.366 moles),vinylmethyldichlorosilane (31.04 g, 0.22 moles) and toluene (506.1 g)was added to the cooled water within 2 minutes, followed by stirring for5 minutes with the removal of ice-water bath (the maximum temperature ofthe solution was up to 75° C. during the reaction). The reaction mixturewas transferred into a 2 L round bottom flask with a bottom drain andthen the aqueous layer was removed. DI water (84.8 g) was added to theremained materials, followed by heating at 80° C. for 10 minutes andthen cooling down and removing the aqueous phase. The remained materialswas added by a mixture of 2-propanol (21.2 g) and DI water (63.6 g),followed by heating at 80° C. for 10 minutes and removing aqueous phase,repeating this step for several times until the final wash water phasehad a pH of 4.0. The reaction mixture was then heated at reflux toremove residual water via azeotropic distillation. The synthesizedD^(Vi)T^(Ph) resin was dried by using a rotavapor at 120° C. The productwas a crunchy solid at room temperature a yield of 335 g, containing 8mole % Vi.

(ii) Preparation of D^(Vi)RLs (3.7 mole % Vi): A 500 mL 4-neck roundbottom flask was charged with D^(Vi) _(0.08)T^(Ph) _(0.92) resin (72 g,0.55 moles Si) and toluene (59.3 g) under nitrogen. The flask wasequipped with a thermometer, Teflon stir paddle, and a Dean Starkapparatus attached to a water-cooled condenser (Dean Stark was prefilledwith toluene). The reaction mixture was heated at reflux (113° C.) for30 minutes with 0.03 g water removed. The reaction solution was cooledto 108° C., followed by quickly adding MTA/ETA capped silanol terminatedPhMe siloxane (which was synthesized by adding MTA/ETA (50/50, 1.85 g,0.00813 moles Si) to the siloxane (88 g, 0.645 moles Si, DP=129) andstirring them at room temperature in a glove box for 1 hour). Thereaction mixture was heated at reflux for 2 hours under nitrogen with0.7 g water removed. The reaction solution was cooled to 108° C. againand charged with MTA/ETA (50/50, 1.25 g, 0.0055 moles Si), followed byrefluxing for 1 hour with 0.27 g water removed, and then the reactionmixture was cooled to 90° C. and added with DI water (7.37 g), followedby refluxing to remove water via azeotropic distillation. Theadding-removing water was repeated for three times. Finally the solidcontent of the solution was increased to about 70 wt. % by distillingand removing some volatiles (38.3 g) at 118° C. The synthesizedD^(Vi)RLs solution was clear and colorless, and contains 3.7 mole % Vi.

Example 6: Preparation of D^(Vi)-Modified Resin-Linear Block PolymersHaving 3.5 Mole % Vi

A 500 mL 4-neck round bottom flask was charged with phenyl-T resin (72g, 0.527 moles Si, Dow Corning 217 Flake) and toluene (59.3 g) undernitrogen. The flask was equipped with a thermometer, Teflon stir paddle,and a Dean Stark apparatus attached to a water-cooled condenser (DeanStark was prefilled with toluene). The reaction mixture was heated atreflux (113° C.) for 30 minutes with 0.1 g water removed. The reactionsolution was cooled to 108° C., followed by quickly adding MTA cappedsilanol terminated PhMe siloxane (which was synthesized by adding MTA(methyltriacetoxysilane, 1.79 g, 0.00813 moles Si) to the siloxane (88g, 0.645 moles Si, DP=129) and stirring them at room temperature in aglove box for 1 hour). The reaction mixture was heated at reflux for 2hours under nitrogen with 0.95 g water removed. The reaction solutionwas cooled to 108° C. again and charged with VMDA(vinylmethyldiacetoxysilane, 8.14 g, 0.0432 moles Si), followed byrefluxing for 1 hour with 0.65 g water removed, and then the reactionmixture was cooled to 90° C. and added with DI water (17.14 g), followedby refluxing to remove water via azeotropic distillation. The reactionsolution was cooled to 108° C. again and added with MTA (2.67 g, 0.0121moles Si), followed by refluxing for 1 hour, and then the reactionmixture was cooled to 90° C. and added with DI water (17.14 g), followedby refluxing to remove water via azeotropic distillation (thisadding-removing water was repeated for two times). Finally the solidcontent of the solution was increased to about 70 wt. % by distillingand removing some volatiles (36.5 g) at 118° C. The synthesizedD^(Vi)RLs solution was clear and colorless, and contains 3.5 mole % Vi.

Example 7: Preparation of T^(Vi)-Modified Resin-Linear Block PolymersHaving 4.5 Mole % Vi

A 500 mL 4-neck round bottom flask was charged with phenyl-T resin (72g, 0.527 moles Si, Dow Corning 217 Flake) and toluene (59.3 g) undernitrogen. The flask was equipped with a thermometer, Teflon stir paddle,and a Dean Stark apparatus attached to a water-cooled condenser (DeanStark was prefilled with toluene). The reaction mixture was heated atreflux (113° C.) for 30 minutes with 0.1 g water removed. The reactionsolution was cooled to 108° C., followed by quickly adding MTA cappedsilanol terminated PhMe siloxane (which was synthesized by addingMTA/ETA (50/50, 1.85 g, 0.00813 moles Si) to the siloxane (88 g, 0.645moles Si, DP=129) and stirring them at room temperature in a glove boxfor 1 hour). The reaction mixture was heated at reflux for 2 hours undernitrogen with 0.94 g water removed. The reaction solution was cooled to108° C. again and charged with VTA (vinyltriacetoxysilane, 12.84 g,0.0553 moles Si), followed by refluxing for 1 hour with 0.71 g waterremoved, and then the reaction mixture was cooled to 90° C. and addedwith DI water (17.14 g), followed by refluxing to remove water viaazeotropic distillation. The adding-removing water was repeated forthree times with total 59.1 g water removed. Finally the solid contentof the solution was increased to about 70 wt. % by distilling andremoving some volatiles (38.6 g) at 118° C. The synthesized T^(Vi)RLssolution was clear and colorless, and contains 4.5 mole % Vi.

Example 8: Preparation of D^(Vi)-Modified Resin-Linear Block PolymersHaving 1 Mole % Vi

A 500 mL 4-neck round bottom flask was charged with phenyl-T resin (72g, 0.535 moles Si, Dow Corning 217 Flake) and toluene (59.3 g) undernitrogen. The flask was equipped with a thermometer, Teflon stir paddle,and a Dean Stark apparatus attached to a water-cooled condenser (DeanStark was prefilled with toluene). The reaction mixture was heated atreflux (113° C.) for 30 minutes with 0.01 g water removed. The reactionsolution was cooled to 108° C., followed by quickly adding MTA cappedsilanol terminated PhMe siloxane (which was synthesized by adding MTA(methyltriacetoxysilane, 1.79 g, 0.00813 moles Si) to the siloxane (88g, 0.645 moles Si, DP=129) and stirring them at room temperature in aglove box for 1 hour). The reaction mixture was heated at reflux for 2hours under nitrogen with 0.67 g water removed. The reaction solutionwas cooled to 108° C. again and charged with VMDA(vinylmethyldiacetoxysilane, 2.33 g, 0.0124 moles Si), followed byrefluxing for 1 hour with 0.24 g water removed, and then the reactionmixture was cooled to 90° C. and added with DI water (14 g), followed byrefluxing to remove water via azeotropic distillation. The reactionsolution was cooled to 108° C. again and added with MTA (1.77 g, 0.00804moles Si), followed by refluxing for 1 hour, and then the reactionmixture was cooled to 90° C. and added with DI water (15.4 g), followedby refluxing to remove water via azeotropic distillation (thisadding-removing water was repeated for two times). Finally the solidcontent of the solution was increased to about 70 wt. % by distillingand removing some volatiles (31.5 g) at 118° C. The synthesizedD^(Vi)RLs solution was clear and colorless, and contains 1 mole % Vi.

Example 9: Preparation of D^(Vi)-Modified Resin-Linear Block PolymersHaving 2 Mole % Vi

A 500 mL 4-neck round bottom flask was charged with phenyl-T resin (180g, 1.318 moles Si, Dow Corning 217 Flake) and toluene (138.6 g) undernitrogen. The flask was equipped with a thermometer, Teflon stir paddle,and a Dean Stark apparatus attached to a water-cooled condenser (DeanStark was prefilled with toluene). The reaction mixture was heated atreflux for 30 minutes with 0.54 g water removed. The reaction solutionwas cooled to 108° C., followed by quickly adding MTA/ETA capped silanolterminated PhMe siloxane (which was synthesized by adding 50/50 MTA/ETA(methyltriacetoxysilane/ethyltriacetoxysilane, 4.24 g, 0.0187 moles Si)to the siloxane (220 g, 1.614 moles Si, DP=181) and stirring them atroom temperature in a glove box for 1 hour). The reaction mixture washeated at reflux for 2 hours under nitrogen with 2.01 g water removed.The reaction solution was cooled to 108° C. again and charged with VMDA(vinylmethyldiacetoxysilane, 11.91 g, 0.0633 moles Si), followed byrefluxing for 1 hour with 1.05 g water removed, and then the reactionmixture was cooled to 90° C. and added with DI water (47.8 g), followedby refluxing to remove water via azeotropic distillation. The reactionsolution was cooled to 108° C. again and added with 50/50 MTA/ETA (21.57g, 0.0949 moles Si), followed by refluxing for 1 hour, and then thereaction mixture was cooled to 90° C. and added with DI water (47.8 g),followed by refluxing to remove water via azeotropic distillation (thisadding-removing water was repeated for two times). Same water treatmentwas performed three times, and finally the solid content of the solutionwas increased to about 70 wt. % by distilling and removing somevolatiles (103.6 g) at 118° C. The synthesized D^(Vi)RLs solution wasclear and colorless, and contains 2 mole % Vi.

Example 10: D^(Vi)RLs with 2 Mole % Vi and 1 Ppm Pt Catalysts

D^(Vi)RL in Example 9 was used to prepare example 10 with the loading of1 ppm Pt catalysts.

Example 11: T^(Vi)RLs with 2 Mole % Vi

A 500 mL 4-neck round bottom flask was charged with phenyl-T resin (180g, 1.318 moles Si, Dow Corning 217 Flake) and toluene (148.2 g) undernitrogen. The flask was equipped with a thermometer, Teflon stir paddle,and a Dean Stark apparatus attached to a water-cooled condenser (DeanStark was prefilled with toluene). The reaction mixture was heated atreflux for 30 minutes with 1.05 g water removed. The reaction solutionwas cooled to 108° C., followed by quickly adding MTA/ETA capped silanolterminated PhMe siloxane (which was synthesized by adding 50/50 MTA/ETA(methyltriacetoxysilane/ethyltriacetoxysilane, 4.43 g, 0.0195 moles Si)to the siloxane (220 g, 1.614 moles Si, DP=181) and stirring them atroom temperature in a glove box for 1 hour). The reaction mixture washeated at reflux for 2 hours under nitrogen with 2.05 g water removed.The reaction solution was cooled to 108° C. again and charged with VTA(vinyltriacetoxysilane, 14.29 g, 0.0615 moles Si) and 50/50 MTA/ETA(14.48 g, 0.0637 moles Si), followed by refluxing for 1 hour, and thenthe reaction mixture was cooled to 90° C. and added with DI water (39.1g), followed by refluxing to remove water via azeotropic distillation.Water treatment (39.1 g DI water) was repeated for two more times.Finally the solid content of the solution was increased to about 70 wt.% by distilling and removing some volatiles (113 g) at 118° C. Thesynthesized D^(Vi)RLs solution was clear and colorless, and contains 2mole % Vi.

Example 12: Hydrosilylation Cure Formulations

Hydrosilylation cure formulations containing resin-linear organosiloxaneblock copolymers made according to Examples 2-11 were prepared tocontain the amounts of resin linear organosiloxane block copolymer,compounds having the formula R¹ _(q)R³ _((3-q))SiO(R¹₂SiO_(2/2))_(m)SiR³ _((3-q))R¹ _(q), and Pt catalyst shown in Table 2.The resin-linear organosiloxane block copolymer was prepared as a 60 wt.% solution in toluene, followed by pouring the solution into a Tefloncoated aluminum pan to make 0.5 to 2 mm thick films. The transparent,solid, uncured film was formed evenly in the aluminum pan after leavingthe pan in hood overnight to remove the solvent toluene. The pancontaining the solid film was heated in oven at 70° C. for severalhours, then at 120° C. for 1 hour, and finally at 160° C. for 3 hours toobtain the cured film.

Comparative Example 1

A 12 L 3-neck round bottom flask was charged with phenyl-T resin (1800g, 13.18 moles Si, Dow Corning 217 flake) and toluene (1482 g) undernitrogen. The flask was equipped with a thermometer, Teflon stir paddle,and a Dean Stark apparatus attached to a water-cooled condenser (DeanStark was prefilled with toluene). The reaction mixture was heated atreflux for 30 minutes with 8.18 g water removed. The reaction solutionwas cooled to 108° C., followed by quickly adding MTA/ETA(methyltriacetoxysilane/ethyltriacetoxysilane) capped silanol terminatedPhMe siloxane (which was synthesized by adding 50/50 wt % MTA/ETA(methyltriacetoxysilane/ethyltriacetoxysilane) (46.96 g, 0.207 moles Si)to the siloxane (2200 g, 16.13 moles Si, DP=127) and stirring them atroom temperature in a glove box for 1 hour). The reaction mixture washeated at reflux for 2 hours under nitrogen with 14.66 g water removed.The reaction solution was cooled to 108° C. again and charged with 50/50wt % MTA/ETA (methyltriacetoxysilane/ethyltriacetoxysilane) (314.49 g,1.348 moles), followed by refluxing for 1 hour with 0.56 g waterremoved, and then the reaction mixture was cooled to 90° C. and addedwith deionized (DI) water (430 g), followed by refluxing to remove watervia azeotropic distillation. The adding-removing water process wasrepeated two times with a total 1045.9 g aqueous phase removed. Finallythe solid content of the solution was increased to about 70 wt. % bydistilling and removing some volatiles (1331.4 g) at 118° C. Thesynthesized resin-linear solution was clear and colorless. Theresin-linear block copolymer was cured in the presence of 50 ppm DBU togive DBU cured resin-linear solid compositions.

Comparative Example 2

The resin linear solution was synthesized using the same proceduresgiven in Comparative Example 1. The resin-linear block copolymer wascured in the presence of Al(acac)₃ containing 100 ppm Al for preparingAl cured resin-linear solid compositions.

Comparative Example 3

The components set forth below are mixed using a vacuum planetary mixer,Thinky ARV-310, for 2 minutes at 1600 rpm under 2 kPa to form a liquidcomposition:

Component 1: Average Unit Molecular Formula:(Me₂ViSiO_(1/2))_(0.25)(PhSiO_(3/2))_(0.75); 5.8 g;

Component 2: Average Unit Molecular Formula:Me₂ViSiO(MePhSiO)₂₅OSiMe₂Vi; 1.8 g;

Component 3: Average Unit Molecular Formula: HMe₂SiO(Ph₂SiO)SiMe₂H; 2.0g;

Component 4: Average Unit Molecular Formula: (HMe₂SiO)1/2/0.60(PhSiO_(3/2))_(0.4); 0.24 g;

Component 5: Average Unit Molecular Formula:

(Me₂ViSiO_(1/2))_(0.18) (PhSiO_(3/2))_(0.54)(EpMeSiO)_(0.28) wherein(Ep=glicidoxypropyl); 0.23 g;

Component 6: Average Unit Molecular Formula: Cyclic (ViSiMeO_(1/2))_(n);0.02 g;

1-Ethynyl-1-Cyclohexanol, 240 ppm; and

Pt Catalyst (1,3-divinyltetramethylsiloxane complex), 2.5 ppm.

Comparative Example 4 Preparation of M^(Vi)-Modified Resin-Linear BlockPolymers Having 2.7 Mole % Vi Via Hydrosylilation Reaction

(i) Preparation of M^(Vi) _(0.147)T^(Ph) _(0.853) resin: A 3 L 3-neckround bottom flask was loaded DI water (1011.9 g), followed by coolingto 4° C. with ice-water bath. The flask was equipped with a thermometer,Teflon stir paddle, and a water-cooled condenser. A pre-mixed solutionof phenyltrichlorosilane (444.26 g, 2.1 moles),vinyldimethylchlorosilane (48.26 g, 0.4 moles) and toluene (481.5 g) wasadded to the cooled water over 3 minutes (the maximum temperature of thesolution was up to 71° C. during the reaction), followed by immediatelyremoving ice-water bath and heating to 80° C. for 15 minutes. Thereaction mixture was transferred into a 2 L round bottom flask with abottom drain, and the aqueous layer was removed, followed by heating at80° C. for 15 minutes again to promote molecular weight growth. DI water(80.25 g) was added to the remained materials, followed by heating at80° C. for 10 minutes and then cooling down and removing the aqueousphase. The remained materials was added by a mixture of 2-propanol(20.06 g) and DI water (60.19 g), followed by heating at 80° C. for 10minutes and removing aqueous phase (repeating this step for severaltimes until the final wash water phase had a pH of 4.0. The reactionmixture was then heated at reflux to remove residual water viaazeotropic distillation. The synthesized M^(Vi) _(0.147)T^(Ph) _(0.853)resin was dried by using a rotavapor at 120° C. The product was a“crunchy” solid at room temperature with the yield of 332 g, containing14.7 mole % Vi.

(ii) Preparation of SiH terminated PhMe siloxane (DP=129, M^(H) ₂D^(Ph)₁₂₉): A 1 L dry 3-neck round bottom flask was charged with silanolterminated PhMe siloxane (D^(Ph) ₁₂₉(OH)₂, 300.8 g, 2.207 moles Si,0.0265 moles silanol), toluene (450 g) and triethylamine (TEA, 4.47 mL,0.032 moles) under nitrogen, followed by stirring for 10 minutes.dimethylchlorosilane (3.53 mL, 0.0318 moles) was slowly added to theflask by a syringe within 10 minutes. White salt precipitates wereformed within 1 minute after adding the chlorosilane. The reactionmixture was stirred under nitrogen and room temperature for 3 hours,followed by adding 1 mL DI water to quench the unreacted cholorsilane.Finally, 10 g anhydrous Na₂SO₄ was added to the flask, followed bystirring under air overnight to completely dry the solution. In thesecond day, the reaction solution was filtered with 1.2 μm filter paperunder 30 psi to remove the white salt precipitates. The solvent andsmall amount of TEA and quenched vinyl precursors were removedcompletely by using Rotavapor at 80° C. and 5 mm Hg vacuum. The M^(H)₂D^(Ph) ₁₂₉ product is clear colorless liquid materials with highviscosity.

(iii) Preparation of M^(Vi)RLs^(SysD) (2.7 mole % Vi): A 500 mL 4-neckround bottom flask was charged with M^(Vi) _(0.147)T^(Ph) _(0.853) resin(72 g, 0.56 moles Si), M^(H) ₂D^(Ph) ₁₂₉ (88 g) and toluene (59.3 g)under nitrogen. The flask was equipped with a thermometer, Teflon stirpaddle, and a Dean Stark apparatus attached to a water-cooled condenser(Dean Stark was prefilled with toluene). The reaction mixture was heatedto 90° C., followed by adding Pt catalyst (TSA-276, 4 g, 2.5 ppm Ptbased on total solid weight). The reaction mixture was heated at refluxfor 2.5 hours during which samples were taken for IR to monitor theconsumption of SiH. The reaction was complete after 2 hour refluxingwith 0.63 g water removed. The reaction solution was cooled to 108° C.,followed by adding the SiH-terminated siloxane M^(H)D^(Ph2)M^(H) (7.46g, y 0.0224 moles) and refluxing for 2 hours. The reaction was completeafter 2 hours with 0.31 g water removed (monitored by IR for SiH).Finally, the solid content of the solution was increased to about 60 wt.% by distilling and removing some volatiles at 118° C. The synthesized60% M^(Vi)RLs^(SysD) solution was clear, colorless and viscous, andcontains 2.7 mole % Vi.

Some physical and chemical characteristics of the resin-linearorganosiloxanes made according to Examples 2-11 are given below in Table1.

TABLE 1 Mw Vi SiOH Resin-linears (g/mole) mol % mol % Example 2 540633.5 14.5 Example 3 69300 2 18.8 Example 4 51481 3.7 19.3 Example 5 660123.7 20.3 Example 6 50579 3.5 18.8 Example 7 98949 4.5 18 Example 8110173 1 21.2 Example 9 89571 2 18.2 Example 11 95722 2 16.3

These novel compositions comprising resin-linear organosiloxanes of theembodiments of the present invention have both vinyl functionality andsilanol mol % higher than 1 mole %. This enables both single curethrough vinyl, for example using Si—H hydrosilylation, but also dualcure through vinyl/Si—H and SiOH/SiOH condensation, for example.

TABLE 2 Cure speed Compound of the formula Initial cure (Pa/min) atResin-linear R¹ _(q)R³ _((3-q))SiO(R¹ ₂SiO_(2/2))_(m)SiR³ _((3-q))R¹_(q) Catalyst Vi temperature a heating rate (amount in g) (amount, inmg) (ppm)* (mol %) (° C.) of 5° C./min Example 2 M^(H)D^(Ph2)M^(H) Pt3.5 108 4.88 (20) (931) (2.5), (M^(Vi)RL) Example 3 M^(H)D^(Ph2)M^(H) Pt2 118 1.63 (20) (551) (2.5) (M^(Vi)RL) Example 4 M^(H)D^(Ph2)M^(H) Pt3.7 96 1.27 (20) (972) (2.5) (M^(Vi)RL) Example 5 M^(H)D^(Ph2)M^(H) Pt3.7 116 2.73 (20) (967) (2.5) (D^(Vi)RL) Example 6 M^(H)D^(Ph2)M^(H) Pt3.5 127 2.88 (20) (918) (2.5) (D^(Vi)RL) Example 7 M^(H)D^(Ph2)M^(H) Pt4.5 148 2.23 (20) (1200) (2.5) (T^(Vi)RL) Example 8 M^(H)D^(Ph2)M^(H) Pt1 152 1.55 (20) (258) (2.5) (D^(Vi)RL) Example 9 M^(H) ₆₀T^(Ph) ₄₀ Pt 2N/A N/A (20) (245) (2.5) (D^(Vi)RL) Example 10 M^(H) ₆₀T^(Ph) ₄₀ Pt 2N/A N/A (20) (245) (1) (D^(Vi)RL) Example 11 M^(H) ₆₀T^(Ph) ₄₀ Pt 2 N/AN/A (20) (245) (2.5) (T^(Vi)RL) Comparative DBU 117 1.31 Example 1 (50)(20) Comparative Al(acac)₃ 153 1.26 Example 2 (100, based (20) on totalsolid wt.)) Comparative Pt N/A 55 1.7  Example 3 (2.5) ComparativeM^(H)D^(Ph2)M^(H) Pt 2.7 110 2.68 Example 4 (721) (2.5) (M^(Vi)RL)*Karstedt's catalyst, and contains 2:3 ratio ofPt:vinyl(CH₃)₂SiOSi(CH₃)₂vinyl. [SiH]/[Vi] = 1 for all samples. “N/A”indicates that the data were not obtained.

The cure speed data shown in Table 2 shows that the resin-linearorganosiloxane block copolymers made according to Examples 2-11 exhibitcure speeds comparable to the cure speeds observed for resin-linearorganosiloxane block copolymers that can only be cured via condensationin the presence of a DBU or Al(acac)₃ catalyst. See data for ComparativeExamples 1 and 2. Moreover, the resin-linear organosiloxane blockcopolymers made according to Examples 2-11 all exhibit faster curespeeds than resin linear organosiloxane block copolymers made accordingto the method described in Comparative Example 2.

The resin-linear organosiloxane block copolymers made according toExamples 2-11 were curable when they contained a phosphor (e.g., Ce:YAGused up to 50 wt. % as compared to total solids). In addition, theresin-linear organosiloxane block copolymers made according to Examples2-11 all were shelf stable at room temperature (i.e., at 25° C.) andstandard pressure (1 atm) for at least 15 weeks, exhibiting a change inthe G′_(min) of less than about 50% (e.g., less than about 25%, lessthan about 20%, less than about 15%, less than about 10%, less thanabout 5%, less than about 3%, about 0%; from about 0% to about 50%, fromabout 3% to about 25%, about 5% to about 20% or from about 15% to about45%) in 15 weeks. In contrast, resin-linear organosiloxane blockcopolymers made according to Comparative Example 4 exhibited a change inthe G′_(min) of over 200% in 15 weeks; and resin-linear organosiloxaneblock copolymers made according to Comparative Example 3 exhibited achange in the G′_(min) of over 1300% in one week. These resultsdemonstrate that resin-linear organosiloxane block copolymers of theembodiments of the present invention achieve significantly better shelfstability than other materials known in the art that are cured viahydrosilylation. See, e.g., Comparative Example 3.

Color (before and after aging), Young's modulus data (before and afteraging), and tan 6 data for resin-linear organosiloxane block copolymersmade according to Examples 2-11 and Comparative Examples 1-4 are givenin Table 3.

TABLE 3 Color (CIE Young's b* value) Modulus Tan δ at Color (CIE b*after aging Young's after aging Tan δ at 200° C. after value) before 72h at Modulus 48 h at 200° C. aging 48 h Example aging* 235° C. beforeaging 225° C. before aging at 225° C. Example 2 0.54 4.375 78 1640.00997 0.0803 Example 3 0.52 4.814 75.6 123.1 0.117 N/A Example 4 0.494.289 95.2 142.2 0.0379 0.0988 Example 5 0.18 4.53 95.5 136.2 0.1640.0751 Example 6 0.27 4.9 90 143 0.0522 0.0859 Example 7 0.17 4.586107.8 193.4 0.140 N/A Example 8 0.31 5.1 81.6 102 N/A N/A Example 9 0.63.6 96.8 121 N/A N/A Example 10 0.53 3.1 91.8 111.6 N/A N/A Example 110.58 3.8 75 119.6 N/A N/A Comparative 0.27 3.8 105.9 118.8 0.182 0.121 Example 1 Comparative 0.4 19.8 75 139.2 0.32 N/A Example 2 Comparative0.24 12.5 14.1 Too brittle 0 0    Example 3 Comparative 0.41 6.07 3.34425.7 0.005 N/A Example 4 *The b* values shown in Table 3 were obtainedfrom samples with thickness of about 1 mm by using BYK Colorimeter.“N/A” indicates that the data were not obtained.

The data shown in Table 3 show that resin-linear organosiloxane blockcopolymers made according to certain embodiments of the presentinvention have a ratio of CIE b* values before and after aging of lessthan a 10 after aging for 72 h at 235° C. (e.g., a ratio of less thanabout 9, less than about 8, less than about 7, less than about 6, orless than about 5 after aging 72 h at 235° C.; or a ratio from about a 2to about a 10, 3 to about 9, or from about a 5 to about 10 after agingfor 72 h at 235° C.). Resin-linear organosiloxane block copolymers madeaccording to certain other embodiments of the present invention have aratio of CIE b* values before and after aging of less than a 30 afteraging for 72 h at 235° C. (e.g., less than about a 25, less than about20 or less than about 15 after aging; or from about a 14-fold to about a30-fold, 15-fold to about 20-fold, or from about a 20-fold to about a30-fold change in color after aging for 72 h at 235° C.). In contrast,the resin-linear organosiloxane block copolymers made according toComparative Examples 2 and 3 exhibit an unacceptable ratio of CIE b*values before and after aging for 72 h at 235° C. of about 50. In someembodiments, resin-linear organosiloxane block copolymers made accordingto certain embodiments of the present invention exhibit CIE b* valuesafter aging for 72 h at 235° C. of no more than about 6 (e.g., about 6or less, about 5 or less, about 4 or less or about 3 or less; or fromabout 3 to about 6 or from about 4 to about 6).

The data shown in Table 3 also shows that resin-linear organosiloxaneblock copolymers made according to certain embodiments of the presentinvention have an acceptably high Young's Modulus at room temperaturebefore aging, and the Young's modulus does not change significantlyafter aging, such that the resin-linear organosiloxane block copolymersbecome brittle after aging.

TABLE 4 R_(ΔG′) at 23° C. (MPa/hr)* CIE b* After 500 h CIE b* after 500h Vi aging at before aging at Example Type mol % 225° C. aging 225° C.Example 3 D^(Vi)RL 2 0.45 0.63 6.47 Example 9 T^(Vi)RL 2 0.69 0.59 8.15Example 11 M^(Vi)RL 2 0.49 0.71 9.72 *R_(ΔG′): the modulus change ratemeasured at 23° C. before and after 500 hour aging at 225° C.

The data shown in Table 4 shows that resin-linear organosiloxane blockcopolymers made according to certain embodiments of the presentinvention shows high thermal stability even after thermally aging at225° C. for 500 hours. The less modulus change rate and the lower b*value change of D^(Vi)RL after 500 hour aging indicate the benefit ofD^(Vi)RL over M^(Vi)RL or T^(Vi)RL in thermal stability.

One significant advantage of resin-linear organosiloxane blockcopolymers made according to certain embodiments of the presentinvention is that they are significantly and surprisingly less prone tothe elimination of benzene when the T groups comprise phenyl. In someembodiments, resin-linear organosiloxane block copolymers made accordingto certain embodiments of the present invention generate less than 200ppm benzene after 30 minutes at 180° C. (e.g., less than 150 ppm, lessthan 125 ppm, less than 100 ppm, less than 75 ppm, less than 50 ppm,less than 25 ppm, less than 20 ppm, less than 15 ppm, less than 10 ppm,or less than 6 ppm benzene after 30 minutes at 180° C.; or from about 0ppm to about 200 ppm, from about 10 ppm to about 100 ppm, from about 25ppm to about 100 ppm, from about 2 to about 20 ppm, from about 10 ppm toabout 20 ppm or from about 10 to about 18 ppm benzene after 30 minutesat 180° C.).

Another significant advantage of resin-linear organosiloxane blockcopolymers made according to certain embodiments of the presentinvention is that they is that they are significantly and surprisinglyless prone to phosphor inhibition after curing relative to resin-linearorganosiloxane block copolymers that are cured with typical condensationcatalysts, e.g. comparative examples 1 and 2. In addition, the curespeed of the resin-linear organosiloxane block copolymers is much lesssensitive to the loading of phosphors, e.g., the initial temperature forcure does not change with the variation of phosphor loading. Forexample, the initial temperature of cure, defined as the temperaturewhere G′ increases in a temperature scan after the initial drop withtemperature corresponding to melt flow, changes less than 50° C., lessthan 40° C., less than 30° C., less than 20° C. or less than 15° C. Inaddition, a tan delta above 0.05 can be maintained after aging,something that is not accomplished with materials known in the art thatare cured via hydrosilylation. See, e.g., Comparative Example 4.

The invention claimed is:
 1. An organosiloxane block copolymercomprising: 40 to 90 mole percent disiloxy units of the formula [R¹₂SiO_(2/2)], 10 to 60 mole percent trisiloxy units of the formula[R²SiO_(3/2)], 0.5 to 35 mole percent silanol groups [≡SiOH]; wherein:each R¹, at each occurrence, is independently a C₁ to C₃₀ hydrocarbyl ora C₁ to C₃₀ hydrocarbyl group comprising at least one aliphaticunsaturated bond, each R², at each occurrence, is independently a C₁ toC₃₀ hydrocarbyl or a C₁ to C₃₀ hydrocarbyl group comprising at least onealiphatic unsaturated bond; wherein: the disiloxy units [R¹ ₂SiO_(2/2)]are arranged in linear blocks having an average of from 100 to 300disiloxy units [R¹ ₂SiO_(2/2)] per linear block; the trisiloxy units[R²SiO_(3/2)] are arranged in non-linear blocks having a molecularweight of at least 500 g/mole; at least 30% of the non-linear blocks arecrosslinked with each other; each linear block is linked to at least onenon-linear block via —Si—O—Si— linkages; the organosiloxane blockcopolymer has a weight average molecular weight of at least 20,000g/mole; and the organosiloxane block copolymer comprises from about 0.5to about 4.5 mole % C₁ to C₃₀ hydrocarbyl group comprising at least onealiphatic unsaturated bond.
 2. The organosiloxane block copolymer ofclaim 1, wherein the organosiloxane block copolymer comprises 12 to 22mole percent silanol groups [≡SiOH].
 3. The organosiloxane blockcopolymer of claim 1, wherein the organosiloxane block copolymer has aweight average molecular weight of about 40,000 g/mole to about 250,000g/mole.
 4. The organosiloxane block copolymer of claim 1, wherein theorganosiloxane block copolymer comprises 1 to 35 mole percent silanolgroups [≡SiOH].
 5. The organosiloxane block copolymer of claim 1,wherein the organosiloxane block copolymer comprises 30 to 60 molepercent trisiloxy units of the formula [R²SiO_(3/2)].
 6. A compositioncomprising the reaction product of: A) a resin linear organosiloxaneblock copolymer comprising: 40 to 90 mole percent disiloxy units of theformula [R¹ ₂SiO_(2/2)], 10 to 60 mole percent trisiloxy units of theformula [R²SiO_(3/2)], 0.5 to 35 mole percent silanol groups [≡SiOH];wherein: each R¹, at each occurrence, is independently a C₁ to C₃₀hydrocarbyl free of aliphatic unsaturation, each R², at each occurrence,is independently a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation;wherein: the disiloxy units [R¹ ₂SiO_(2/2)] are arranged in linearblocks having an average of from 50 to 300 disiloxy units [R¹₂SiO_(2/2)] per linear block, the trisiloxy units [R²SiO_(3/2)] arearranged in non-linear blocks having a molecular weight of at least 500g/mole, at least 30% of the non-linear blocks are crosslinked with eachother, each linear block is linked to at least one non-linear block; andthe organosiloxane block copolymer has a weight average molecular weightof at least 20,000 g/mole; and B) a compound of the formula R¹R² ₂SiXwherein each R¹, at each occurrence, is independently a C₁ to C₃₀hydrocarbyl free of aliphatic unsaturation or a C₁ to C₃₀ hydrocarbylgroup comprising at least one aliphatic unsaturated bond, each R², ateach occurrence, is independently a C₁ to C₃₀ hydrocarbyl free ofaliphatic unsaturation or a C₁ to C₃₀ hydrocarbyl group comprising atleast one aliphatic unsaturated bond, and X is a hydrolyzable groupchosen from —OR⁴, F, Cl, Br, I, —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, whereinR⁴ is hydrogen or a C₁ to C₆ alkyl group that may be optionallysubstituted; wherein the reaction product is an organosiloxane blockcopolymer and the organosiloxane block copolymer comprises from about0.5 to about 5 mole % C₁ to C₃₀ hydrocarbyl group comprising at leastone aliphatic unsaturated bond.
 7. The composition of claim 6, whereinthe resin linear organosiloxane block copolymer has a weight averagemolecular weight of about 40,000 g/mole to about 250,000 g/mole.
 8. Thecomposition claim 6, wherein the organosiloxane block copolymercomprises 1 to 35 mole percent silanol groups [≡SiOH].
 9. Thecomposition of claim 6, wherein the organosiloxane block copolymercomprises 30 to 60 mole percent trisiloxy units of the formula[R²SiO_(3/2)].
 10. A composition comprising the reaction product of: A)a linear organosiloxane having the formula:R¹ _(3-p)(E)_(p)SiO(R¹ ₂SiO_(2/2))_(n)Si(E)_(p)R¹ _(3-p), wherein eachR¹, at each occurrence, is independently a C₁ to C₃₀ hydrocarbyl free ofaliphatic unsaturation, n is 50 to 300, E is a hydrolyzable group chosenfrom —OR⁴, F, Cl, Br, I, —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ ishydrogen or a C₁ to C₆ alkyl group, and each p is, independently, 1; 2or 3; and B) an organosiloxane resin comprising unit formula:[R¹₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e),wherein: each R¹, at each occurrence, is independently a C₁ to C₃₀hydrocarbyl free of aliphatic unsaturation or a C₁ to C₃₀ hydrocarbylgroup comprising at least one aliphatic unsaturated bond, each R², ateach occurrence, is independently a C₁ to C₃₀ hydrocarbyl free ofaliphatic unsaturation or a C₁ to C₃₀ hydrocarbyl group comprising atleast one aliphatic unsaturated bond, wherein the organosiloxane resincomprises 0.5 to 35 mole % silanol groups [≡SiOH], and the subscripts a,b, c, d, and e represent the mole fraction of each siloxy unit presentin the organosiloxane resin and range as follows: a is about 0 to about0.6, b is about 0 to about 0.6, c is about 0 to about 1, d is about 0 toabout 1, e is about 0 to about 0.6, with the provisos that b+c+d+e>0 anda+b+c+d+e≦1; wherein the reaction product is an organosiloxane blockcopolymer and the organosiloxane block copolymer comprises from about0.5 to about 5 mole C₁ to C₃₀ hydrocarbyl group comprising at least onealiphatic unsaturated bond.
 11. A composition comprising the reactionproduct of: A) a linear organosiloxane having the formula:R¹ _(3-p)(E)_(p)SiO(R¹ ₂SiO_(2/2))_(n)Si(E)_(p)R¹ _(3-p), wherein eachR¹, at each occurrence, is independently a C₁ to C₃₀ hydrocarbyl free ofaliphatic unsaturation, n is 50 to 300, E is a hydrolyzable group chosenfrom —OR⁴, F, Cl, Br, I, —OC(O)R⁴, —N(R⁴)₂, or —ON═CR⁴ ₂, wherein R⁴ ishydrogen or a C₁ to C₆ alkyl group, and each p is, independently, 1, 2or 3, and B) an organosiloxane resin comprising unit formula:[R¹₂R²SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e),wherein: each R¹, at each occurrence, is independently a C₁ to C₃₀hydrocarbyl free of aliphatic unsaturation, each R², at each occurrence,is independently a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation,wherein the organosiloxane resin comprises 0.5 to 35 mole % silanolgroups [≡SiOH], and the subscripts a, b, c, d, and e represent the molefraction of each siloxy unit present in the organosiloxane resin andrange as follows: a is about 0 to about 0.6, b is about 0 to about 0.6,c is about 0 to about 1, d is about 0 to about 1, e is about 0 to about0.6, with the provisos that b+c+d+e>0 and a+b+c+d+e≦1; and C) a compoundof the formula R¹ _(q)SiX_(4-q) wherein each R¹, at each occurrence, isindependently a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation ora C₁ to C₃₀ hydrocarbyl group comprising at least one aliphaticunsaturated bond, q is 0, 1 or 2, and, each X is independently ahydrolyzable group chosen from —OR⁴, F, Cl, Br, I, —OC(O)R⁴, —N(R⁴)₂, or—ON═CR⁴ ₂, wherein R⁴ is hydrogen or a C₁ to C₆ alkyl group that may beoptionally substituted; wherein the reaction product is anorganosiloxane block copolymer and the organosiloxane block copolymercomprises from about 0.5 to about 5 mole % C₁ to C₃₀ hydrocarbyl groupcomprising at least one aliphatic unsaturated bond.
 12. The compositionof claim 11, wherein the product of the contacting between A) and B) iscontacted with C).
 13. The composition of claim 6, wherein the reactionproduct is contacted with a compound of the formula R⁵ _(q)SiX_(4-q),wherein each R⁵ is independently a C₁ to C₈ hydrocarbyl or a C₁ to C₈halogen-substituted hydrocarbyl; and each X is independently ahydrolyzable group chosen from —OR⁴, F, Cl, Br, I, —OC(O)R⁴, —N(R⁴)₂, or—ON═CR⁴ ₂, wherein R⁴ is hydrogen or a C₁ to C₆ alkyl group that may beoptionally substituted.
 14. The composition of claim 10, wherein E isacetoxy and p is
 1. 15. The composition of claim 6 further comprising acompound having unit formula:[R¹₂SiO_(1/2)]_(a)[R¹R²SiO_(2/2)]_(b)[R¹SiO_(3/2)]_(c)[R²SiO_(3/2)]_(d)[SiO_(4/2)]_(e)comprising 0 to 35 mole % silanol groups [≡SiOH], wherein: each R¹, ateach occurrence, is independently H, a silane radical of the formula—[R⁵R⁶Si]_(k)[R⁵R⁶SiH] (wherein R⁵, R⁶ are independently a H or a C₁ toC₃₀ hydrocarbyl free of aliphatic unsaturation, k is an integer from 0to 10) or a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation, eachR², at each occurrence, is independently H or, a silane radical of theformula —[R⁵R⁶Si]_(k)[R⁵R⁶SiH] (wherein R⁵, R⁶ are independently a H ora C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation, k is an integerfrom 0 to 10) a C₁ to C₃₀ hydrocarbyl free of aliphatic unsaturation,wherein the subscripts a, b, c, d, and e represent the mole fraction ofeach siloxy unit present and range as follows: a is about 0 to about0.6, b is about 0 to about 0.6, c is about 0 to about 1, d is about 0 toabout 1, e is about 0 to about 0.6, with the provisos that: b+c+d+e>0and a+b+c+d+e≦1, and at least 1 mole % of R¹ and/or R² are H or SiHcontaining silane radical.
 16. The composition of claim 6 furthercomprising a hydrosilylation catalyst.
 17. The composition of claim 6,further comprising free resin that is not part of the block copolymer.18. The composition of claim 6, wherein the composition is curable. 19.The curable composition of claim 18, wherein the curable composition hasa cure speed in Pa/min of from about 1 to about 20 Pa/min at a heatingrate of 5° C./min.
 20. The curable composition of claim 18, wherein thecurable composition is curable via at least two curing mechanisms. 21.The curable composition of claim 20, wherein said at least two curingmechanisms comprise hydrosylilation cure and condensation cure.
 22. Thecomposition of claim 6, wherein the composition is solid.
 23. Thecomposition of claim 22, further comprising free resin that is not partof the block copolymer.
 24. The composition of claim 22, wherein thesolid composition is a solid film composition.
 25. The composition ofclaim 22, wherein the solid film composition has an opticaltransmittance of at least 95% at a film thickness of 0.5 mm or greater.26. The cured product of the compositions of claim
 6. 27. The curedproduct of claim 26, wherein the product is cured in the absence of acondensation catalyst.
 28. The cured product of claim 26, wherein theproduct is cured in the presence of a phosphor or a filler.
 29. Thecured product of claim 26, wherein the ratio of the Young's modulus ofthe cured product after aging for 50 hours at 225° C. and the Young'smodulus before aging is less than
 3. 30. The cured product of claim 26,wherein the cured product generates less than 200 ppm benzene after 30minutes at 180° C.
 31. The cured product of claim 26, wherein the CIE b*value after aging for 72 h at 235° C. is no more than about 6.